Implantable cochlear system with integrated components and lead characterization

ABSTRACT

Cochlear implant systems can include a cochlear electrode, a stimulator in electrical communication with the cochlear electrode, a sensor configured to receive a stimulus signal and generate an input signal based on the received stimulus signal, and a signal processor in communication with the stimulator and the sensor. The signal processor can include an analog filtering stage configured to generate an analog filtered signal from a received input signal and a digital filtering stage configured to generate a digitally filtered signal from the analog filtered signal. The analog filtering stage and digital filtering stage can be used to normalize the frequency response of the digitally filtered signal with respect to the stimulus signal.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/808,634, filed Feb. 21, 2019, the contents of whichare incorporated herein by reference.

BACKGROUND

A cochlear implant is an electronic device that may be at leastpartially implanted surgically into the cochlea, the hearing organ ofthe inner ear, to provide improved hearing to a patient. Cochlearimplants may include components that are worn externally by the patientand components that are implanted internally in the patient.

External components may include a microphone, a processor, and atransmitter. Cochlear implants may detect sounds via an ear levelmicrophone that conveys these sounds to a wearable processor. Someprocessors may be worn behind the patient's ear. An electronic signalfrom the processor may be sent to a transmission coil worn externallybehind the ear over the implant. The transmission coil may send a signalto the implant receiver, located under the patient's scalp.

Internal components may include a receiver and one or more electrodes.Some cochlear implants may include additional processing circuitry amongthe internal components. The receiver may direct signals to one or moreelectrodes that have been implanted within the cochlea. The responses tothese signals may then be conveyed along the auditory nerve to thecortex of the brain where they are interpreted as sound.

Some cochlear implants may be fully implanted and include a mechanismfor measuring sound similar to a microphone, signal processingelectronics, and means for directing signals to one or more electrodesimplanted within the cochlea. Fully implanted cochlear implantstypically do not include a transmission coil or a receiver coil.

Internal components of such cochlear implant systems typically requireelectrical power to operate. Thus, a power supply is typically includedalong with the other internal components. However, performance of suchpower supplies often degrades over time, and the power supply mayrequire replacement. Additionally, processing circuitry technologycontinues to advance quickly. Improvements to processing technology overtime may render the processing technology in the implanted processingcircuitry outdated. Thus, there may be times when it is advantageous toreplace/upgrade the processing circuitry.

However, such replacement procedures can be difficult. The location ofthe implanted internal components is not the most amenable to surgicalprocedures and tends not to fully heal after many incisions.Additionally, replacement of some components, such as a signalprocessor, can require removing and reintroducing components such aselectrical leads into the patient's cochlear tissue, which can bedamaging to the tissue and negatively impact the efficacy of cochlearstimulation.

Additionally, different challenges exist for communicating electricalsignals through a patient's body. For example, safety standards canlimit the amount of current that can safely flow through a patient'sbody (particularly DC current). Additionally, the patient's body can actas an undesired signal path between different components within the body(e.g., via contact with the housing or “can” of each component). Thiscan lead to reduced signal strength and/or undesired communication orinterference between components. In some cases, electrical signals mayeven stimulate undesired regions of the patient's cochlear tissue,interfering with the efficacy of the cochlear implant.

SUMMARY

Some aspects of the disclosure are generally directed toward cochlearimplant systems. Such systems can include a cochlear electrode, astimulator in electrical communication with the cochlear electrode, aninput source, and a signal processor. The signal processor can beconfigured to receive an input signal from the input source and output astimulation signal to the stimulator based on the received input signaland a transfer function of the signal processor.

In some examples, the signal processor includes an analog processingstage and a digital processing stage. In some such examples, the signalprocessor is configured to receive an input signal from an input sourceand input the received input signal to the analog processing stage togenerate an analog processed signal. The signal processor can input theanalog processed signal to the digital processing stage to generate adigitally processed signal. In some examples, the signal processor isconfigured such that the digitally processed signal corresponds to anormalized stimulus signal having reduced gain variability across arange of frequencies and compensating for variability in the frequencyresponse of the middle ear sensor.

In some embodiments, the analog processing stage and/or the digitalprocessing stage are adjustable to normalize the frequency response ofthe combined analog processing stage and digital processing stage. Insome examples, normalizing the frequency response makes a ratio of adigital processed signal to a received corresponding stimulus signalapproximately consistent across a plurality of frequencies or frequencyranges.

Some aspects of the disclosure relate to a method for compensating forvariability in a middle ear sensor. In some examples, methods includereceiving a stimulus signal via a middle ear sensor and generating, viathe middle ear sensor, an input signal based on the stimulus signal.Methods can include applying an analog filter to the generated inputsignal to generate an analog filtered signal and applying a digitalfilter to the generated analog filtered signal to generate a digitallyfiltered signal.

In some examples, methods include measuring a frequency response of thedigitally filtered signal and/or the analog filtered signal with respectto the input signal and adjusting the digital filter to normalize thefrequency response of the digitally filtered signal with respect to thestimulus signal. In some examples, such methods further include applyinga plurality of stimulus signals to the middle ear sensor having knownfrequency content. In some such examples, measuring the frequencyresponse of the digitally filtered signal with respect to the stimulussignal is performed for each of the plurality of stimulus signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic illustration of a fully implantable cochlearimplant system.

FIG. 2 shows an embodiment of a fully-implantable cochlear implant.

FIGS. 3A and 3B are exemplary illustrations showing communication withthe signal processor.

FIGS. 4 and 5 illustrate embodiments of an exemplary middle ear sensorfor use in conjunction with anatomical features of a patient.

FIG. 6 shows an illustration of an exemplary detachable connector.

FIG. 7 shows an exemplary cochlear implant system in a patient that isnot fully physically developed, such as a child.

FIG. 8 is a process-flow diagram illustrating an exemplary process forinstalling and/or updating an implantable cochlear implant system into apatient.

FIG. 9 is a schematic diagram illustrating an exemplary implantablesystem including an acoustic stimulator.

FIG. 10A is a high level electrical schematic showing communicationbetween the implantable battery and/or communication module and thesignal processor.

FIG. 10B illustrates an exemplary schematic diagram illustrating acochlear electrode having a plurality of contact electrodes and fixedlyor detachably connected to an electrical stimulator.

FIG. 11A shows a high level schematic diagram illustrating an exemplarycommunication configuration between an implantable battery and/orcommunication module, a signal processor, and a stimulator in anexemplary cochlear implant system.

FIG. 11B is a schematic diagram illustrating exemplary electricalcommunication between an implantable battery and/or communication moduleand a signal processor in a cochlear implant system according to someembodiments.

FIG. 12A is an alternative high-level schematic diagram illustrating anexemplary communication configuration between an implantable batteryand/or communication module, a signal processor, and a stimulator.

FIG. 12B is an alternative schematic diagram illustrating exemplaryelectrical communication between an implantable battery and/orcommunication module and a signal processor in a cochlear implant systemsimilar to that shown in FIG. 12A.

FIG. 12C is another alternative schematic diagram illustrating exemplaryelectrical communication between an implantable battery and/orcommunication module and a signal processor in a cochlear implant systemsimilar to that shown in FIG. 12A.

FIG. 12D is high-level schematic diagram illustrating exemplaryelectrical communication between an implantable battery and/orcommunication module and a signal processor in a cochlear implant systemsimilar to that shown in FIG. 12A.

FIG. 13A shows an exemplary schematic illustration of processor andstimulator combined into a single housing.

FIG. 13B shows a simplified cross-sectional view of theprocessor/stimulator shown in FIG. 13A taken along lines B-B.

FIG. 14A is a schematic diagram showing an exemplary signal processingconfiguration for adapting to variability in a sensor frequencyresponse.

FIG. 14B shows an exemplary gain vs. frequency response curve forsignals at various stages in the processing configuration.

FIG. 15 is a process flow diagram illustrating an exemplary process forestablishing a preferred transfer function for a patient.

FIG. 16 is a process flow diagram illustrating an exemplary process forestablishing a preferred transfer function for a patient.

FIG. 17 is a process flow diagram showing an exemplary method of testingthe efficacy of one or more sounds using one or more transfer functionsvia pre-processed signals.

FIG. 18 is a schematic representation of an exemplary database ofpre-processed sound signals.

FIG. 19 is a schematic diagram illustrating possible communicationbetween a variety of system components according to some embodiments ofa fully-implantable system.

FIG. 20 is a schematic diagram showing establishing a secure wirelessconnection between various components in an implantable system.

FIG. 21 shows a process flow diagram showing an exemplary method forpairing a charger with an implanted system.

FIG. 22 shows a process flow diagram showing an exemplary method forpairing another device with an implanted system using a paired charger.

FIG. 23 is a chart showing the various parameters that are adjustable byeach of a variety of external devices.

FIG. 24 shows an example configuration of an interfacing deviceconfigured to assist in system calibration.

FIG. 25 is a process flow diagram showing an example process forcalibrating an implanted system.

FIG. 26 shows an example embodiment wherein the cochlear implant systemcomprises components implanted for both sides of the wearer (e.g. forboth their right ear and their left ear

DETAILED DESCRIPTION

FIG. 1 shows a schematic illustration of a fully implantable cochlearimplant system. The system of FIG. 1 includes a middle ear sensor 110 incommunication with a signal processor 120. The middle ear sensor 110 canbe configured to detect incoming sound waves, for example, using the earstructure of a patient. The signal processor 120 can be configured toreceive a signal from the middle ear sensor 110 and produce an outputsignal based thereon. For example, the signal processor 120 can beprogrammed with instructions to output a certain signal based on areceived signal. In some embodiments, the output of the signal processor120 can be calculated using an equation based on received input signals.Alternatively, in some embodiments, the output of the signal processor120 can be based on a lookup table or other programmed (e.g., in memory)correspondence between the input signal from the middle ear sensor 110and the output signal. While not necessarily based explicitly on afunction, the relationship between the input to the signal processor 120(e.g., from the middle ear sensor 110) and the output of the signalprocessor 120 is referred to as the transfer function of the signalprocessor 120.

The system of FIG. 1 further includes a cochlear electrode 116 implantedinto the cochlear tissues of a patient. The cochlear electrode 116 is inelectrical communication with an electrical stimulator 130, which can beconfigured to provide electrical signals to the cochlear electrode 116in response to input signals received by the electrical stimulator 130.In some examples, the cochlear electrode 116 is fixedly attached to theelectrical stimulator 130. In other examples, the cochlear electrode 116is removably attached to the electrical stimulator 130. As shown, theelectrical stimulator 130 is in communication with the signal processor120. In some embodiments, the electrical stimulator 130 provideselectrical signals to the cochlear electrode 116 based on output signalsfrom the signal processor 120.

In various embodiments, the cochlear electrode 116 can include anynumber of contact electrodes in electrical contact with different partsof the cochlear tissue. In such embodiments, the electrical stimulator130 can be configured to provide electrical signals to any number ofsuch contact electrodes to stimulate the cochlear tissue. For example,in some embodiments, the electrical stimulator 130 is configured toactivate different contact electrodes or combinations of contactelectrodes of the cochlear electrode 116 in response to different inputsignals received from the signal processor 120. This can help thepatient differentiate between different input signals.

During exemplary operation, the middle ear sensor 110 detects audiosignals, for example, using features of the patient's ear anatomy asdescribed elsewhere herein and in U.S. Patent Publication No.2013/0018216, which is hereby incorporated by reference in its entirety.The signal processor 120 can receive such signals from the middle earsensor 110 and produce an output to the electrical stimulator 130 basedon the transfer function of the signal processor 120. The electricalstimulator 130 can then stimulate one or more contact electrodes of thecochlear electrode 116 based on the received signals from the signalprocessor 120.

Referring to FIG. 2, an embodiment of a fully-implantable cochlearimplant is shown. The device in this embodiment includes a processor 220(e.g., signal processor), a sensor 210, a first lead 270 connecting thesensor 210 to the processor 220, and a combination lead 280 attached tothe processor 220, wherein combination lead 280 contains both a groundelectrode 217 and a cochlear electrode 216. The illustrated processor220 includes a housing 202, a coil 208, first female receptacle 271 andsecond female receptacle 281 for insertion of the leads 270 and 280,respectively.

In some embodiments, coil 208 can receive power and/or data from anexternal device, for instance, including a transmission coil (notshown). Some such examples are described in U.S. Patent Publication No.2013/0018216, which is incorporated by reference. In other examples,processor 220 is configured to receive power and/or data from othersources, such as an implantable battery and/or communication module asshown in FIG. 1. Such battery and/or communication module can beimplanted, for example, into the pectoral region of the patient in orderto provide adequate room for larger equipment (e.g., a relatively largebattery) for prolonged operation (e.g., longer battery life).Additionally, in the event a battery needs eventual replacement, areplacement procedure in the patient's pectoral region can be performedseveral times without certain vascularization issues that can arise nearthe location of the cochlear implant. For example, in some cases,repeated procedures (e.g., battery replacement) near the cochlearimplant can result in a decreased ability for the skin in the region toheal after a procedure. Placing a replaceable component such as abattery in the pectoral region can facilitate replacement procedureswith reduced risk for such issues.

FIGS. 3A and 3B are exemplary illustrations showing communication with asignal processor. For example, referring to FIGS. 3A and 3B, theprocessor 320, includes a housing 302, a coil 308, and a generic lead380 are shown. The lead 380 is removable and can be attached to theprocessor 320 by insertion of a male connector 382 of the generic lead380 into any available female receptacle, shown here as 371 or 381. FIG.3A shows the processor 320 with the generic lead 380 removed. FIG. 3Bshows the processor 320 with the generic lead 380 attached. The maleconnector 382 is exchangeable, and acts as a seal to prevent or minimizefluid transfer into the processor 320.

FIGS. 4 and 5 illustrate embodiments of an exemplary middle ear sensorfor use in conjunction with anatomical features of a patient. Referringto FIG. 4, an embodiment of the sensor 410 of a fully-implantablecochlear implant is shown. Here, the sensor 410 is touching the malleus422. The sensor may include a cantilever 432 within a sensor housing434. The sensor 410 may be in communication with the processor 420 by atleast two wires 436 and 438, which may form a first lead (e.g., 270).Both wires can be made of biocompatible materials but need notnecessarily be the same biocompatible material. Examples of suchbiocompatible materials can include tungsten, platinum, palladium, andthe like. In various embodiments, one, both, or neither of wires 436 and438 are coated with a coating and/or disposed inside a casing, such asdescribed in U.S. Patent Publication No. 2013/0018216, which isincorporated by reference.

The illustrated cantilever 432 includes at least two ends, where atleast one end is in operative contact with the tympanic membrane or oneor more bones of the ossicular chain. The cantilever 432 may be alaminate of at least two layers of material. The material used may bepiezoelectric. One example of such a cantilever 432 is a piezoelectricbimorph, which is well-known in the art (see for example, U.S. Pat. No.5,762,583). In one embodiment, the cantilever is made of two layers ofpiezoelectric material. In another embodiment, the cantilever is made ofmore than two layers of piezoelectric material. In yet anotherembodiment, the cantilever is made of more than two layers ofpiezoelectric material and non-piezoelectric material.

The sensor housing 434 of the sensor 410 may be made of a biocompatiblematerial. In one embodiment, the biocompatible material may be titaniumor gold. In another embodiment, the sensor 410 may be similar to thesensor described in U.S. Pat. No. 7,524,278 to Madsen et al., oravailable sensors, such as that used in the ESTEEM™ implant (EnvoyMedical, Corp., St. Paul, Minn.), for example. In alternativeembodiments, the sensor 410 may be an electromagnetic sensor, an opticalsensor, or an accelerometer. Accelerometers are known in the art, forexample, as described in U.S. Pat. No. 5,540,095.

Referring to FIG. 5, an embodiment of the sensor 510 of afully-implantable cochlear implant is shown. Also shown are portions ofthe subject's anatomy, which includes, if the subject is anatomicallynormal, at least the malleus 522, incus 524, and stapes 526 of themiddle ear 528, and the cochlea 548, oval window 546, and round window544 of the inner ear 542. Here, the sensor 510 is touching the incus524. The sensor 510 in this embodiment can be as described for theembodiment of sensor 410 shown in FIG. 4. Further, although not shown ina drawing, the sensor 510 may be in operative contact with the tympanicmembrane or the stapes, or any combination of the tympanic membrane,malleus 522, incus 524, or stapes 526.

FIGS. 4 and 5 illustrate an exemplary middle ear sensor for use withsystems described herein. However, other middle ear sensors can be used,such as sensors using microphones or other sensors capable of receivingan input corresponding to detected sound and outputting a correspondingsignal to the signal processor. Additionally or alternatively, systemscan include other sensors configured to output a signal representativeof sound received at or near a user's ear, such as a microphone or otheracoustic pickup located in the user's outer ear or implanted under theuser's skin. Such devices may function as an input source, for example,to the signal processor such that the signal processor receives an inputsignal from the input source and generates and output one or morestimulation signals according to the received input signal and thesignal processor transfer function.

Referring back to FIG. 1, the signal processor 120 is shown as being incommunication with the middle ear sensor 110, the electrical stimulator130, and the implantable battery and/or communication module 140. Asdescribed elsewhere herein, the signal processor 120 can receive inputsignals from the middle ear sensor 110 and/or other input source(s) andoutput signals to the electrical stimulator 130 for stimulating thecochlear electrode 116. The signal processor 120 can receive data (e.g.,processing data establishing or updating the transfer function of thesignal processor 120) and/or power from the implantable battery and/orcommunication module 140. In some embodiments, the signal processor 120can communicate with such components via inputs such as those shown inFIG. 3.

In some embodiments, the implantable battery and/or communication module140 can communicate with external components, such as a programmer 100and/or a battery charger 102. The battery charger 102 can wirelesslycharge the battery in the implantable battery and/or communicationmodule 140 when brought into proximity with the implantable batteryand/or communication module 140 in the pectoral region of the patient.Such charging can be accomplished, for example, using inductivecharging. The programmer 100 can be configured to wirelessly communicatewith the implantable battery and/or communication module 140 via anyappropriate wireless communication technology, such as Bluetooth, Wi-Fi,and the like. In some examples, the programmer 100 can be used to updatethe system firmware and/or software. In an exemplary operation, theprogrammer 100 can be used to communicate an updated signal processor120 transfer function to the implantable battery and/or communicationmodule 140. In various embodiments, the programmer 100 and charger 102can be separate devices or can be integrated into a single device.

In the illustrated example of FIG. 1, the signal processor 120 isconnected to the middle ear sensor 110 via lead 170. In someembodiments, lead 170 can provide communication between the signalprocessor 120 and the middle ear sensor 110. In some embodiments, lead170 can include a plurality of isolated conductors providing a pluralityof communication channels between the middle ear sensor 110 and thesignal processor 120. The lead 170 can include a coating such as anelectrically insulating sheath to minimize any conduction of electricalsignals to the body of the patient.

In various embodiments, one or more communication leads can bedetachable such that communication between two components can bedisconnected in order to electrically and/or mechanically separate suchcomponents. For instance, in some embodiments, lead 170 includes adetachable connector 171. Detachable connector 171 can facilitatedecoupling of the signal processor 120 and middle ear sensor 110. FIG. 6shows an illustration of an exemplary detachable connector. In theillustrated example, the detachable connector 671 includes a maleconnector 672 and a female connector 673. In the illustrated example,the male connector 672 includes a plurality of isolated electricalcontacts 682 and female connector 673 includes a corresponding pluralityof electrical contacts 683. When the male connector 672 is inserted intothe female connector 673, contacts 682 make electrical contact withcontacts 683. Each corresponding pair of contacts 682, 683 can provide aseparate channel of communication between components connected via thedetachable connector 671. In the illustrated example, four channels ofcommunication are possible, but it will be appreciated that any numberof communication channels are possible. Additionally, while shown asindividual circumferentially extending contacts 683, otherconfigurations are possible.

In some embodiments, male 672 and female 673 connectors are attached atthe end of leads 692, 693, respectively. Such leads can extend fromcomponents of the implantable cochlear system. For example, withreference to FIG. 1, in some embodiments, lead 170 can include a firstlead extending from the middle ear sensor 110 having one of a male(e.g., 672) or a female (e.g., 673) connector and a second leadextending from the signal processor 120 having the other of the male orfemale connector. The first and second leads can be connected atdetachable connector 171 in order to facilitate communication betweenthe middle ear sensor 110 and the signal processor 120.

In other examples, a part of the detachable connector 171 can beintegrated into one of the middle ear sensor 110 and the signalprocessor 120 (e.g., as shown in FIG. 3). For example, in an exemplaryembodiment, the signal processor 120 can include a female connector(e.g., 673) integrated into a housing of the signal processor 120. Lead170 can extend fully from the middle ear sensor 110 and terminate at acorresponding male connector (e.g., 672) for inserting into the femaleconnector of the signal processor 120. In still further embodiments, alead (e.g., 170) can include connectors on each end configured todetachably connect with connectors integrated into each of thecomponents in communication. For example, lead 170 can include two maleconnectors, two female connectors, or one male and one female connectorfor detachably connecting with corresponding connectors integral to themiddle ear sensor 110 and the signal processor 120. Thus, lead 170 mayinclude two or more detachable connectors.

Similar communication configurations can be established for detachableconnector 181 of lead 180 facilitating communication between the signalprocessor 120 and the stimulator 130 and for detachable connector 191 oflead 190 facilitating communication between the signal processor 120 andthe implantable battery and/or communication module 140. Leads (170,180, 190) can include pairs of leads having corresponding connectorsextending from each piece of communicating equipment, or connectors canbe built in to any one or more communicating components.

In such configurations, each of the electrical stimulator 130, signalprocessor 120, middle ear sensor 110, and battery and/or communicationmodule can each be enclosed in a housing, such as a hermetically sealedhousing comprising biocompatible materials. Such components can includefeedthroughs providing communication to internal components enclosed inthe housing. Feedthroughs can provide electrical communication to thecomponent via leads extending from the housing and/or connectorsintegrated into the components.

In a module configuration such as that shown in FIG. 1, variouscomponents can be accessed (e.g., for upgrades, repair, replacement,etc.) individually from other components. For example, as signalprocessor 120 technology improves (e.g., improvements in size,processing speed, power consumption, etc.), the signal processor 120implanted as part of the system can be removed and replacedindependently of other components. In an exemplary procedure, animplanted signal processor 120 can be disconnected from the electricalstimulator 130 by disconnecting detachable connector 181, from themiddle ear sensor 110 by disconnecting detachable connector 171, andfrom the implantable battery and/or communication module 140 bydisconnecting detachable connector 191. Thus, the signal processor 120can be removed from the patient while other components such as theelectrical stimulator 130, cochlear electrode 116, middle ear sensor110, and battery and/or communication module can remain in place in thepatient.

After the old signal processor is removed, a new signal processor can beconnected to the electrical stimulator 130, middle ear sensor 110, andimplantable battery and/or communication module 140 via detachableconnectors 181, 171, and 191, respectively. Thus, the signal processor(e.g., 120) can be replaced, repaired, upgraded, or any combinationthereof, without affecting the other system components. This can reduce,among other things, the risk, complexity, duration, and recovery time ofsuch a procedure. In particular, the cochlear electrode 116 can be leftin place in the patient's cochlea while other system components can beadjusted, reducing trauma to the patient's cochlear tissue.

Such modularity of system components can be particularly advantageouswhen replacing a signal processor 120, such as described above.Processor technology continues to improve and will likely continue tomarkedly improve in the future, making the signal processor 120 a likelycandidate for significant upgrades and/or replacement during thepatient's lifetime. Additionally, in embodiments such as the embodimentshown in FIG. 1, the signal processor 120 communicates with many systemcomponents. For example, as shown, the signal processor 120 is incommunication with each of the electrical stimulator 130, the middle earsensor 110, and the implantable battery and/or communication module 140.Detachably connecting such components with the signal processor 120(e.g., via detachable connectors 181, 171, and 191) enables replacementof the signal processor 120 without disturbing any other components.Thus, in the event of an available signal processor 120 upgrade and/or afailure of the signal processor 120, the signal processor 120 can bedisconnected from other system components and removed.

While many advantages exist for a replaceable signal processor 120, themodularity of other system components can be similarly advantageous, forexample, for upgrading any system component. Similarly, if a systemcomponent (e.g., the middle ear sensor 110) should fail, the componentcan be disconnected from the rest of the system (e.g., via detachableconnector 171) and replaced without disturbing the remaining systemcomponents. In another example, even a rechargeable battery included inthe implantable battery and/or communication module 140 may eventuallywear out and need replacement. The implantable battery and/orcommunication module 140 can be replaced or accessed (e.g., forreplacing the battery) without disturbing other system components.Further, as discussed elsewhere herein, when the implantable batteryand/or communication module 140 is implanted in the pectoral region ofthe patient, such as in the illustrated example, such a procedure canleave the patient's head untouched, eliminating unnecessarily frequentaccess beneath the skin.

While various components are described herein as being detachable, invarious embodiments, one or more components configured to communicatewith one another can be integrated into a single housing. For example,in some embodiments, signal processor 120 can be integrally formed withthe stimulator 130 and cochlear electrode 116. For example, in anexemplary embodiment, processing and stimulation circuitry of a signalprocessor 120 and stimulator 130 can be integrally formed as a singleunit in a housing coupled to a cochlear electrode. Cochlear electrodeand the signal processor/stimulator can be implanted during an initialprocedure and operate as a single unit.

In some embodiments, while the integral signalprocessor/stimulator/cochlear electrode component does not get removedfrom a patient due to potential damage to the cochlear tissue into whichthe cochlear electrode is implanted, system upgrades are still possible.For example, in some embodiments, a module signal processor may beimplanted alongside the integral signal processor/stimulator componentand communicate therewith. In some such examples, the integral signalprocessor may include a built-in bypass to allow a later-implantedsignal processor to interface directly with the stimulator. Additionallyor alternatively, the modular signal processor can communicate with theintegral signal processor, which may be programmed with a unity transferfunction. Thus, in some such embodiments, signals from the modularsignal processor may be essentially passed through the integral signalprocessor unchanged so that the modular signal processor effectivelycontrols action of the integral stimulator. Thus, in variousembodiments, hardware and/or software solutions exist for upgrading anintegrally attached signal processor that may be difficult or dangerousto remove.

Another advantage to a modular cochlear implant system such as shown inFIG. 1 is the ability to implant different system components into apatient at different times. For example, infants and children aretypically not suited for a fully implantable system such as shown inFIG. 1. Instead, such patients typically are candidates to wear atraditional cochlear implant system. For example, FIG. 7 shows anexemplary cochlear implant system in a patient that is not fullyphysically developed, such as a child. The system includes a cochlearelectrode 716 implanted into the cochlear tissue of the patient. Thecochlear electrode 716 of FIG. 7 can include many of the properties ofthe cochlear electrodes described herein. The cochlear electrode 716 canbe in electrical communication with an electrical stimulator 730, whichcan be configured to stimulate portions of the cochlear electrode 716 inresponse to an input signal, such as described elsewhere herein. Theelectrical stimulator 730 can receive input signals from a signalprocessor 720.

In some cases, components such as a middle ear sensor are incompatiblewith a patient who is not fully physically developed. For example,various dimensions within a growing patient's anatomy, such as spacingbetween anatomical structures or between locations on anatomicalstructures (e.g., equipment attachment points) may change as the patientgrows, thereby potentially rendering a middle ear sensor that isextremely sensitive to motion ineffective. Similarly, the undevelopedpatient may not be able to support the implantable battery and/orcommunication module. Thus, the signal processor 720 can be incommunication with a communication device for communicating withcomponents external to the patient. Such communication components caninclude, for example, a coil 708, shown as being connected to the signalprocessor 720 via lead 770. The coil 708 can be used to receive dataand/or power from devices external to the user. For example, microphoneor other audio sensing device (not shown) can be in communication withan external coil 709 configured to transmit data to the coil 708implanted in the patient. Similarly, a power source (e.g., a battery)can be coupled to an external coil 709 and configured to provide powerto the implanted components via the implanted coil 708. Additionally,processing data (e.g., updates to the signal processor 720 transferfunction) can also be communicated to the implanted coil 708 from anexternal coil 709. While generally discussed using coil 708, it will beappreciated that communication between external and implanted components(e.g., the signal processor 720) can be performed using othercommunication technology, such as various forms of wirelesscommunication. As shown, in the embodiment of FIG. 7, the signalprocessor 720 is coupled to the coil 708 via lead 770 and detachableconnector 771. Accordingly, the coil 708 can be detached from the signalprocessor 720 and removed without disrupting the signal processor 720.

When a patient has become fully developed, for example, to the pointthat the patient can safely accommodate a middle ear sensor and animplantable battery and/or communication module, the coil 708 can beremoved and remaining components of the fully implantable system can beimplanted. That is, once a patient is developed, the cochlear implantsystem (e.g., of FIG. 7) can be updated to a fully implantable cochlearimplant system (e.g., of FIG. 1). In some examples, the patient isconsidered sufficiently developed once the patient reaches age 18 oranother predetermined age. Additional or alternative criteria may beused, such as when various anatomical sizes or determined developmentalstates are achieved.

FIG. 8 is a process-flow diagram illustrating an exemplary process forinstalling and/or updating an implantable cochlear implant system into apatient. A cochlear electrode can be implanted in communication with thepatient's cochlear tissue and an electrical stimulator can be implantedin communication with the cochlear electrode (step 850). A signalprocessor can be implanted into the patient (step 852). As describedelsewhere herein, the signal processor can be connected to theelectrical stimulator via a detachable connector (step 854). In examplesin which the signal processor is integrally formed with one or morecomponents, such as the stimulator and cochlear electrode, steps 850,852, and 854 can be combined into a single step comprising implantingthe cochlear electrode, stimulator, and signal processor component.

If, at the time of implementing the process of FIG. 8, it can bedetermined if the patient is considered sufficiently developed (step856). If not, a coil (or other communication device) such as describedwith respect to FIG. 7 can be implanted (step 858). The coil can beconnected to the signal processor via the detachable connector (step860), and the cochlear implant can operate in conjunction with externalcomponents (step 862), such as microphones and external power suppliesand coils.

However, if a patient is, or has become, sufficiently developed (step856), additional components can be implanted into the patient. Forexample, the method can include implanting a middle ear sensor (step864) and connecting the middle ear sensor to the signal processor via adetachable connector (step 866). Additionally, the method can includeimplanting a battery and/or communication module (step 868) andconnecting the battery and/or communication module to the signalprocessor via a detachable connector (step 870). If the patient hadbecome sufficiently developed after having worn a partially externaldevice such as that described with respect to FIG. 7 and steps 858-862,the method can include removing various components that had beenpreviously implanted. For example, a coil, such as implanted in step858, can be disconnected and removed during the procedure of implantingthe middle ear sensor (step 864).

The process of FIG. 8 can be embodied in a method of fitting a patientwith an implantable hearing system. Such a method can include implantinga first system (e.g., the system of FIG. 7) into a patient at a firstage. This can include, for example, performing steps 850-562 in FIG. 8.The method can further include, when the patient reaches a second age,the second age being greater than the first, removing some components ofthe first system (e.g., a coil) and implanting the not-yet implantedcomponents of second system (e.g., the system of FIG. 1), for example,via steps 864-870 of FIG. 8.

Transitioning from the system of FIG. 7 to the system of FIG. 1, forexample, via the process of FIG. 8, can have several advantages. From apatient preference standpoint, some patients may prefer a system that istotally implanted and requires no wearable external components.Additionally, an implanted battery and/or communication module incommunication with the signal processor via lead 190 (and detachableconnector 191) can much more efficiently relay power and/or data to thesignal processor when compared to an external device such as a coil.

Such modular systems provide distinct advantages over previousimplantable or partially implantable cochlear implant systems.Generally, previous systems include several components included into asingle housing implanted into the patient. For example, functionality ofa signal processor, electrical stimulator, and sensor can be enclosed ina single, complex component. If any such aspects of the component fail,which becomes more likely as the complexity increases, the entire modulemust be replaced. By contrast, in a modular system, such as shown inFIG. 1, individual components can be replaced while leaving others inplace. Additionally, such systems including, for example, coil-to-coilpower and/or data communication through the patient's skin alsogenerally communicate less efficiently than an internal connection suchas via the lead 190. Modular systems such as shown in FIGS. 1 and 7 alsoallow for a smooth transition from a partially implantable system for apatient who is not yet fully developed and a fully implantable systemonce the patient has become fully developed.

While often described herein as using an electrical stimulator tostimulate the patient's cochlear tissue via a cochlear electrode, insome examples, the system can additionally or alternatively include anacoustic stimulator. An acoustic stimulator can include, for example, atransducer (e.g., a piezoelectric transducer) configured to providemechanical stimulation to the patient's ear structure. In an exemplaryembodiment, the acoustic stimulator can be configured to stimulate oneor more portions of the patient's ossicular chain via amplifiedvibrations. Acoustic stimulators can include any appropriate acousticstimulators, such as those found in the ESTEEM™ implant (Envoy MedicalCorp., St. Paul, Minn.) or as described in U.S. Pat. Nos. 4,729,366,4,850,962, and 7,524,278, and U.S. Patent Publication No. 20100042183,each of which is incorporated herein by reference in its entirety.

FIG. 9 is a schematic diagram illustrating an exemplary implantablesystem including an acoustic stimulator. The acoustic stimulator can beimplanted proximate the patient's ossicular chain and can be incommunication with a signal processor via lead 194 and detachableconnector 195. The signal processor can behave as described elsewhereherein and can be configured to cause acoustic stimulation of theossicular chain via the acoustic stimulator in response to input signalsfrom the middle ear sensor according to a transfer function of thesignal processor.

The acoustic stimulator of FIG. 9 can be used similarly to theelectrical stimulator as described elsewhere herein. For instance, anacoustic stimulator can be mechanically coupled to a patient's ossicularchain upon implanting the system and coupled to the signal processor vialead 194 and detachable connector 195. Similarly to systems describedelsewhere herein with respect to the electrical stimulator, if thesignal processor requires replacement or repair, the signal processorcan be disconnected from the acoustic stimulator (via detachableconnector 195) so that the signal processor can be removed withoutdisturbing the acoustic stimulator.

In general, systems incorporating an acoustic sensor such as shown inFIG. 9 can operate in the same way as systems described elsewhere hereinemploying an electrical stimulator and cochlear electrode onlysubstituting electrical stimulation for acoustic stimulation. The samemodularity benefits, including system maintenance and upgrades as wellas the ability to convert to a fully implantable system when a patientbecomes sufficiently developed, can be similarly realized using acousticstimulation systems. For example, the process illustrated in FIG. 8 canbe performed in an acoustic stimulation system simply by substitutingthe electrical stimulator and cochlear electrode for an acousticstimulator.

Some systems can include a hybrid system comprising both an electricalstimulator and an acoustic stimulator in communication with the signalprocessor. In some such examples, the signal processor can be configuredto stimulate electrically and/or acoustically according to the transferfunction of the signal processor. In some examples, the type ofstimulation used can depend on the input signal received by the signalprocessor. For instance, in an exemplary embodiment, the frequencycontent of the input signal to the signal processor can dictate the typeof stimulation. In some cases, frequencies below a threshold frequencycould be represented using one of electrical and acoustic stimulationwhile frequencies above the threshold frequency could be representedusing the other of electrical and acoustic stimulation. Such a thresholdfrequency could be adjustable based on the hearing profile of thepatient. Using a limited range of frequencies can reduce the number offrequency domains, and thus the number of contact electrodes, on thecochlear electrode. In other examples, rather than a single thresholdfrequency defining which frequencies are stimulated electrically andacoustically, various frequencies can be stimulated both electricallyand acoustically. In some such examples, the relative amount ofelectrical and acoustic stimulation can be frequency-dependent. Asdescribed elsewhere herein, the signal processor transfer function canbe updated to meet the needs of the patient, including the electricaland acoustic stimulation profiles.

With further reference to FIGS. 1 and 9, in some examples, a system caninclude a shut-off controller 104, which can be configured to wirelesslystop an electrical stimulator 130 from stimulating the patient'scochlear tissue and/or an acoustic stimulator 150 from stimulating thepatient's ossicular chain. For example, if the system is malfunctioningor an uncomfortably loud input sound causes an undesirable level ofstimulation, the user may use the shut-off controller 104 to ceasestimulation from the stimulator 130. The shut-off controller 104 can beembodied in a variety of ways. For example, in some embodiments, theshut-off controller 104 can be integrated into other externalcomponents, such as the programmer 100. In some such examples, theprogrammer 100 includes a user interface by which a user can select anemergency shut-off feature to cease stimulation. Additionally oralternatively, the shut-off controller 104 can be embodied as a separatecomponent. This can be useful in situations in which the patient may nothave immediate access to the programmer 100. For example, the shut-offcontroller 104 can be implemented as a wearable component that thepatient can wear at all or most times, such as a ring, bracelet,necklace, or the like.

The shut-off controller 104 can communicate with the system in order tostop stimulation in a variety of ways. In some examples, the shut-offcontroller 104 comprises a magnet that is detectable by a sensor (e.g.,a Hall-Effect sensor) implanted in the patient, such as in the processorand/or the implantable battery and/or communication module 140. In somesuch embodiments, when the magnet is brought sufficiently close to thesensor, the system can stop stimulation of the cochlear tissue orossicular chain.

After the shut-off controller 104 is used to disable stimulation,stimulation can be re-enabled in one or more of a variety of ways. Forexample, in some embodiments, stimulation is re-enabled after apredetermined amount of time after it had been disabled. In otherexamples, the shut-off controller 104 can be used to re-enablestimulation. In some such examples, the patient brings the shut-offcontroller 104 within a first distance of a sensor (e.g., a magneticsensor) to disable stimulation, and then removes the shut-off controller104. Subsequently, once the patient brings the shut-off controller 104within a second distance of the sensor, stimulation can be re-enabled.In various embodiments, the first distance can be less than the seconddistance, equal to the second distance, or greater than the seconddistance. In still further embodiments, another device such as aseparate turn-on controller (not shown) or the programmer 100 can beused to re-enable stimulation. Any combination of such re-enabling ofstimulation can be used, such as alternatively using either theprogrammer 100 or the shut-off controller 104 to enable stimulation orcombining a minimum “off” time before any other methods can be used tore-enable stimulation.

In some embodiments, rather than entirely disable stimulation, otheractions can be taken, such as reducing the magnitude of stimulation. Forexample, in some embodiments, the shut-off sensor can be used to reducethe signal output by a predetermined amount (e.g., absolute amount,percentage, etc.). In other examples, the shut-off sensor can affect thetransfer function of the signal processor to reduce the magnitude ofstimulation in a customized way, such as according to frequency or otherparameter of an input signal (e.g., from the middle ear sensor).

With reference back to FIG. 1, as described elsewhere herein, theimplantable battery and/or communication module can be used to providepower and/or data (e.g., processing instructions) to other systemcomponents via lead 190. Different challenges exist for communicatingelectrical signals through a patient's body. For example, safetystandards can limit the amount of current that can safely flow through apatient's body (particularly DC current). Additionally, the patient'sbody can act as an undesired signal path from component to component(e.g., via contact with the housing or “can” of each component). Varioussystems and methods can be employed to improve the communication abilitybetween system components.

FIG. 10A is a high level electrical schematic showing communicationbetween the implantable battery and/or communication module and thesignal processor. In the illustrated embodiment, the implantable batteryand/or communication module includes circuitry in communication withcircuitry in the signal processor. Communication between the circuitryin the implantable battery and/or communication module and the signalprocessor can be facilitated by a lead (190), represented by the leadtransfer function. The lead transfer function can include, for example,parasitic resistances and capacitances between the leads connecting theimplantable battery and/or communication module and the signal processorand the patient's body and/or between two or more conductors that makeup the lead (e.g., 191). Signals communicated from the circuitry of theimplantable battery and/or communication module to the circuitry in thesignal processor can include electrical power provided to operate and/orstimulate system components (e.g., the middle ear sensor, signalprocessor, electrical and/or acoustic stimulator, and/or cochlearelectrode) and/or data (e.g., processing data regarding the transferfunction of the signal processor).

As discussed elsewhere herein, the body of the patient provides anelectrical path between system components, such as the “can” of theimplantable battery and/or communication module and the “can” of thesignal processor. This path is represented in FIG. 10A by the flow paththrough R_(Body). Thus, the patient's body can provide undesirablesignal paths which can negatively impact communication betweencomponents. To address this, in some embodiments, operating circuitry ineach component can be substantially isolated from the component “can”and thus the patient's body. For example, as shown, resistance R_(Can)is positioned between the circuitry and the “can” of both theimplantable battery and/or communication module and the signalprocessor.

While being shown as R_(Can) in each of the implantable battery and/orcommunication module and the signal processor, it will be appreciatedthat the actual value of the resistance between the circuitry andrespective “can” of different elements is not necessarily equal.Additionally, R_(Can) need not include purely a resistance, but caninclude other components, such as one or more capacitors, inductors, andthe like. That is, R_(Can) can represent an insulating circuit includingany variety of components that act to increase the impedance betweencircuitry within a component and the “can” of the component. Thus,R_(Can) can represent an impedance between the operating circuitry of acomponent and the respective “can” and the patient's tissue. Isolatingthe circuitry from the “can” and the patient's body acts to similarlyisolate the circuitry from the “can” of other components, allowing eachcomponent to operate with reference to a substantially isolatedcomponent ground. This can eliminate undesired communication andinterference between system components and/or between system componentsand the patient's body.

For example, as described elsewhere herein, in some examples, anelectrical stimulator can provide an electrical stimulus to one or morecontact electrodes on a cochlear electrode implanted in a patient'scochlear tissue. FIG. 10B illustrates an exemplary schematic diagramillustrating a cochlear electrode having a plurality of contactelectrodes and fixedly or detachably connected to an electricalstimulator. As shown, the cochlear electrode 1000 has four contactelectrodes 1002, 1004, 1006, and 1008, though it will be appreciatedthat any number of contact electrodes is possible. As describedelsewhere herein, the electrical stimulator can provide electricalsignals to one or more such contact electrodes in response to an outputfrom the signal processor according to the transfer function thereof anda received input signal.

Because each contact electrode 1002-1008 is in contact with thepatient's cochlear tissue, each is separated from the “can” of theelectrical stimulator (as well as the “cans” of other system components)via the impedance of the patient's tissue, shown as R_(Body). Thus, ifthe circuitry within various system components did not have sufficientlyhigh impedance (e.g., R_(Can)) to the component “can”, electricalsignals may stimulate undesired regions of the patient's cochleartissue. For instance, stimulation intended for a particular contactelectrode (e.g., 1002) may lead to undesired stimulation of othercontact electrodes (e.g., 1004, 1006, 1008), reducing the overallefficacy of the system. Minimizing the conductive paths between systemcomponents (e.g., to the contact electrodes of a cochlear electrode) dueto the patient's body, such as by incorporating impedances betweencomponent circuitry and the corresponding “can” via R_(Can), cantherefore improve the ability to apply an electrical stimulus to only adesired portion of the patient's body.

It will be appreciated that the term R_(Body) is used herein togenerally represent the resistance and/or impedance of the patient'stissue between various components and does not refer to a specificvalue. Moreover, each depiction or R_(Body) in the figures does notnecessarily represent the same value of resistance and/or impedance asthe others.

FIG. 11A shows a high level schematic diagram illustrating an exemplarycommunication configuration between an implantable battery and/orcommunication module, a signal processor, and a stimulator. In theexample of FIG. 11A, the implantable battery and/or communication module1110 is in two-way communication with the signal processor 1120. Forinstance, the implantable battery and/or communication module 1110 cancommunicate power and/or data signals 1150 to the signal processor 1120.In some examples, the power and data signals 1150 can be included in asingle signal generated in the implantable battery and/or communicationmodule 1110 and transmitted to the signal processor 1120. Such signalscan include, for example, a digital signal transmitted with a particularclock rate, which in some embodiments, can be adjustable, for example,via the implantable battery and/or communication module 1110.

In some embodiments, the signal processor 1120 can communicateinformation to the implantable battery and/or communication module 1110(e.g., 1151), for example, feedback information and/or requests for morepower, etc. The implantable battery and/or communication module 1110can, in response, adjust its output to the signal processor 1120 (e.g.,an amplitude, duty cycle, clock rate, etc.) in order to accommodate forthe received feedback (e.g., to provide more power, etc.). Thus, in somesuch examples, the implantable battery and/or communication module 1110can communicate power and data (e.g., 1150) to the signal processor1120, and the signal processor 1120 can communicate various data back tothe implantable battery and/or communication module 1110 (e.g., 1151).

In some embodiments, similar communication can be implemented betweenthe signal processor 1120 and the stimulator 1130, wherein the signalprocessor 1120 provides power and data to the stimulator 1130 (e.g.,1160) and receives data in return from the stimulator 1130 (e.g., 1161).For example, the signal processor 1120 can be configured to outputsignals (e.g., power and/or data) to the stimulator 1130 (e.g., based onreceived inputs from a middle ear sensor or other device) via a similarcommunication protocol as implemented between the implantable batteryand/or communication module 1110 and the signal processor 1120.Similarly, in some embodiments, the stimulator can be configured toprovide feedback signals to the signal processor, for example,representative of an executed stimulation process. Additionally oralternatively, the stimulator may provide diagnostic information, suchas electrode impedance and neural response telemetry or other biomarkersignals.

FIG. 11B is a schematic diagram illustrating exemplary electricalcommunication between an implantable battery and/or communication moduleand a signal processor in a cochlear implant system according to someembodiments. In the illustrated embodiment, the implantable batteryand/or communication module 1110 includes a signal generator 1112configured to output a signal through a lead (e.g., 190) to the signalprocessor 1120. As described with respect to FIG. 11A, in some examples,the signal generator 1112 is configured to generate both data and powersignals (e.g., 1150) for communication to the signal processor 1120. Insome embodiments, the signal generator 1112 generates a digital signalfor communication to the signal processor 1120. The digital signal fromthe signal generator 1112 can be communicated to the signal processor1120 at a particular clock rate. In some examples, the signals aregenerated at approximately 30 kHz. In various examples, data and powerfrequencies can range from approximately 100 Hz to approximately 10 MHz,and in some examples, may be adjustable, for example, by a user.

In the illustrated embodiment, the implantable battery and/orcommunication module 1110 includes a controller in communication withthe signal generator 1112. In some examples, the controller is capableof adjusting communication parameters such as the clock rate of thesignal generator 1112. In an exemplary embodiment, the controller and/orthe signal generator 1112 can communicate with, for example, a patient'sexternal programmer (e.g., as shown in FIG. 1). The controller and/orsignal generator 1112 can be configured to communicate data to thesignal processor 1120 (e.g., 1151), such as updated firmware, signalprocessor 1120 transfer functions, or the like.

As shown, the signal generator 1112 outputs the generated signal to anamplifier 1190 and an inverting amplifier 1192. In some examples, bothamplifiers are unity gain amplifiers. In some examples comprisingdigital signals, the inverting amplifier 1192 can comprise a digital NOTgate. The output from the amplifier 1190 and the inverting amplifier1192 are generally opposite one another and are directed to the signalprocessor 1120. In some embodiments, the opposite nature of the signalsoutput to the signal processor 1120 from amplifiers 1190 and 1192results in a charge-neutral communication between the implantablebattery and/or communication module 1110 and the signal processor 1120,such that no net charge flows through the wearer.

In the illustrated example of FIG. 11B, the receiving circuitry in thesignal processor 1120 comprises a rectifier circuit 1122 that receivessignals (e.g., 1150) from the amplifier 1190 and the inverting amplifier1192. Since the output of one of the amplifiers 1190 and 1192 will behigh, the rectifier circuit 1122 can be configured to receive theopposite signals from the amplifiers 1190 and 1192 and generatetherefrom a substantially DC power output 1123. In various embodiments,the DC power 1123 can be used to power a variety of components, such asthe signal processor 1120 itself, the middle ear sensor, the electricaland/or acoustic stimulator, or the like. The rectifier circuit 1122 caninclude any known appropriate circuitry components for rectifying one ormore input signals, such as a diode rectification circuit or atransistor circuit, for example.

As described elsewhere herein, the implantable battery and/orcommunication module 1110 can communicate data to the signal processor1120. In some embodiments, the controller and/or the signal generator1112 is configured to encode the data for transmission via the outputamplifiers 1190 and 1192. The signal processor 1120 can include a signalextraction module 1124 configured to extract the data signal 1125 fromthe signal(s) (e.g., 1150) communicated to the signal processor 1120 toproduce a signal for use by the signal processor 1120. In some examples,the signal extraction module 1124 is capable of decoding the signal thatwas encoded by the implantable battery and/or communication module 1110.Additionally or alternatively, the signal extraction module 1124 canextract a signal 1125 resulting from the lead transfer function. Invarious examples, the extracted signal 1125 can include, for example, anupdated transfer function for the signal processor 1120, a desiredstimulation command, or other signals that affect operation of thesignal processor 1120.

In the illustrated example, the signal processor 1120 includes acontroller 1126 that is capable of monitoring the DC power 1123 and thesignal 1125 received from the implantable battery and/or communicationmodule 1110. The controller 1126 can be configured to analyze thereceived DC power 1123 and the signal 1125 and determine whether or notthe power and/or signal is sufficient. For example, the controller 1126may determine that the signal processor 1120 is receiving insufficientDC power for stimulating a cochlear electrode according to the signalprocessor 1120 transfer function, or that data from the implantablebattery and/or communication module 1110 is not communicated at adesired rate. Thus, in some examples, the controller 1126 of the signalprocessor 1120 can communicate with the controller 1114 of theimplantable battery and/or communication module 1110 and providefeedback regarding the received communication. Based on the receivedfeedback from the controller 1126 of the signal processor 1120, thecontroller 1114 of the implantable battery and/or communication module1110 can adjust various properties of the signal output by theimplantable battery and/or communication module 1110. For example, thecontroller of the implantable battery and/or communication module 1110can adjust the clock rate of the communication from the signal generator1112 to the signal processor 1120.

In some systems, the transmission efficiency between the implantablebattery and/or communication module 1110 and the signal processor 1120is dependent on the clock rate of transmission. Accordingly, in someexamples, the implantable battery and/or communication module 1110begins by transmitting at an optimized clock rate until a change inclock rate is requested via the signal processor 1120, for example, toenhance data transmission (e.g., rate, resolution, etc.). In otherinstances, if more power is required (e.g., the controller of the signalprocessor 1120 determines the DC power is insufficient), the clock ratecan be adjusted to improve transmission efficiency, and thus themagnitude of the signal received at the signal processor 1120. It willbe appreciated that in addition or alternatively to adjusting a clockrate, adjusting an amount of power transmitted to the signal processor1120 can include adjusting the magnitude of the signal output from thesignal generator 1112. In some embodiments, for example, with respect toFIGS. 11A-B, power and data can be communicated, for example, fromimplantable battery and/or communication module 1110 to the signalprocessor 1120 at a rate of approximately 30 kHz, and can be adjustedfrom there as necessary and/or as requested, for example, by the signalprocessor 1120.

FIG. 12A is an alternative high-level schematic diagram illustrating anexemplary communication configuration between an implantable batteryand/or communication module, a signal processor, and a stimulator. Inthe example of FIG. 12A, the implantable battery and/or communicationmodule 1210 provides signals (e.g., 1250) to the signal processor 1220via a first communication link and is further in two-way communicationfor providing additional signals (e.g., 1251) with the signal processor1220. In the example of FIG. 12A, the implantable battery and/orcommunication module 1210 can provide power signals (e.g., 1250) to thesignal processor 1220 via a communication link and otherwise be intwo-way data communication (1251) with the signal processor 1220 via asecond communication link. In some such examples, the power (1250) anddata (1251) signals can each include digital signals. However, in someembodiments, the power and data signals are transmitted at differentclock rates. In some examples, the clock rate of the data signals is atleast one order of magnitude greater than the clock rate of the powersignals. For example, in an exemplary embodiment, the power signal iscommunicated at a clock rate of approximately 30 kHz, while the datacommunication occurs at a clock rate of approximately 1 MHz. Similarlyto the embodiment described in FIG. 11A, in some examples, the clockrate can be adjustable, for example, via the implantable battery and/orcommunication module 1210.

As described with respect to FIG. 11A, in some embodiments, the signalprocessor 1220 can communicate information to the implantable batteryand/or communication module 1210, for example, feedback informationand/or requests for more power, etc. (e.g., data signals 1251). Theimplantable battery and/or communication module 1210 can, in response,adjust the power and/or data output to the signal processor 1220 (e.g.,an amplitude, duty cycle, clock rate, etc.) in order to accommodate forthe received feedback (e.g., to provide more power, etc.).

In some embodiments, similar communication can be implemented betweenthe signal processor 1220 and the stimulator 1230, wherein the signalprocessor 1220 provides power and data to the stimulator 1230 andreceives data in return from the stimulator 1230. For example, thesignal processor 1220 can be configured to output signals power signals(e.g., 1260) and data signals (e.g., 1261) to the stimulator 1230 (e.g.,based on received inputs from a middle ear sensor or other device). Suchcommunication can be implemented via a similar communication protocol asimplemented between the implantable battery and/or communication module1210 and the signal processor 1220. In some examples, the power signalsprovided to the stimulator 1230 (e.g., 1260) are the same signals (e.g.,1250) received by the signal processor 1220 from the implantable batteryand/or communication module 1210. Additionally, in some embodiments, thestimulator 1230 can be configured to provide feedback signals to thesignal processor 1220 (e.g., 1261), for example, representative of anexecuted stimulation process.

FIG. 12B is an alternative schematic diagram illustrating exemplaryelectrical communication between an implantable battery and/orcommunication module 1210 b and a signal processor 1220 b in a cochlearimplant system similar to that shown in FIG. 12A. In the illustratedembodiment of FIG. 12B, the implantable battery and/or communicationmodule 1210 b includes a power signal generator 1211 and a separatesignal generator 1212. The power signal generator 1211 and signalgenerator 1212 are each configured to output a signal through a lead(e.g., 190) to the signal processor 1220 b. In some embodiments, thepower signal generator 1211 and the signal generator 1212 each generatesdigital signal for communication to the signal processor 1220 b. In somesuch embodiments, the digital signal (e.g., 1250) from the power signalgenerator 1211 can be communicated to the signal processor 1220 b at apower clock rate, while the digital signal (e.g., 1251 b) from thesignal generator 1212 can be communicated to the signal processor 1220 bat a data clock rate that is different from the power clock rate. Forinstance, in some configurations, power and data can be communicatedmost effectively and/or efficiently at different clock rates. In anexemplary embodiment, the power clock rate is approximately 30 kHz whilethe data clock rate is approximately 1 MHz. Utilizing different andseparately communicated power and data signals having different clockrates can increase the transfer efficiency of power and/or data from theimplantable battery and/or communication module 1210 b to the signalprocessor 1220 b.

In the illustrated embodiment, the implantable battery and/orcommunication module 1210 b includes a controller 1214 in communicationwith the power signal generator 1211 and the signal generator 1212. Insome examples, the controller 1214 is capable of adjusting communicationparameters such as the clock rate or content of the signal generator1212 and/or the power signal generator 1211. In an exemplary embodiment,the controller 1214 and/or the signal generator 1212 or power signalgenerator 1211 can communicate with, for example, a patient's externalprogrammer (e.g., as shown in FIG. 1). The controller 1214 and/or signalgenerator 1212 can be configured to communicate data to the signalprocessor 1220 b, such as updated firmware, signal processor 1220 btransfer functions, or the like. Additionally or alternatively, thecontroller 1214 can be configured to transmit signals such as audio orother signals streamed or otherwise received from one or more externaldevices as described elsewhere herein.

As shown, and similar to the example shown in FIG. 11B, the power signalgenerator 1211 outputs the generated signal to an amplifier 1290 and aninverting amplifier 1292. In some examples, both amplifiers are unitygain amplifiers. In some examples comprising digital signals, theinverting amplifier 1292 can comprise a digital NOT gate. The outputfrom the amplifier 1290 and the inverting amplifier 1292 are generallyopposite one another and are directed to the signal processor 1220 b. Inthe illustrated example, the receiving circuitry in the signal processor1220 b comprises a rectifier circuit 1222 that receives signals from theamplifier 1290 and the inverting amplifier 1292. Since the output of oneof the amplifiers 1290 and 1292 will be high, the rectifier circuit 1222can be configured to receive the opposite signals from the amplifiers1290 and 1292 and generate therefrom a substantially DC power output1223.

In various embodiments, the DC power 1223 can be used to power a varietyof components, such as the signal processor 1220 b itself, the middleear sensor, the electrical and/or acoustic stimulator 1230, or the like.The rectifier circuit 1222 can include any known appropriate circuitrycomponents for rectifying one or more input signals, such as a dioderectification circuit or a transistor circuit, for example. In someembodiments, signals from the power signal generator 1211 are generatedat a clock rate that is optimal for transmitting power through the lead(e.g., approximately 30 kHz). In the illustrated example of FIG. 12B,the rectifier circuit 1222 can be arranged in parallel with power linesthat are configured to communicate power signals to other componentswithin the system, such as the stimulator 1230, for example. Forinstance, in some embodiments, the same power signal (e.g., 1250)generated from the power signal generator 1211 and output via amplifiers1290 and 1292 can be similarly applied to the stimulator 1230. In somesuch examples, the stimulator 1230 includes a rectifier circuit 1222similar to the signal processor 1220 b for extracting DC power from thepower signal and the inverted power signal provided by amplifiers 1290and 1292, respectively. In alternative embodiments, the signal processor1220 b can similarly provide signals from a separate power signalgenerator 1211 to provide power signals (e.g., at approximately 30 kHz)to the stimulator 1230 similar to how power is provided from theimplantable battery and/or communication module 1210 b to the signalprocessor 1220 b in FIG. 12B.

In the example of FIG. 12B, the signal generator 1212 outputs a datasignal (e.g., 1251 b) to an amplifier 1294 and an inverting amplifier1296. In some examples, both amplifiers are unity gain amplifiers. Insome examples comprising digital signals, the inverting amplifier 1296can comprise a digital NOT gate. The output from the amplifier 1294 andthe inverting amplifier 1296 are generally opposite one another and aredirected to the signal processor 1220 b.

As described elsewhere herein, in some embodiments, the controller 1214and/or the signal generator 1212 is configured to encode data fortransmission via the output amplifiers 1294 and 1296. The signalprocessor 1220 b can include a signal extraction module 1224 configuredto extract the data from the signal(s) 1225 communicated to the signalprocessor 1220 b to produce a signal 1225 for use by the signalprocessor 1220 b. In some examples, the signal extraction module 1224 iscapable of decoding the signal that was encoded by the implantablebattery and/or communication module 1210 b. Additionally oralternatively, the signal extraction module 1224 can extract a resultingsignal 1225 resulting from the lead transfer function. In variousexamples, the extracted signal can include, for example, an updatedtransfer function for the signal processor 1220 b, a desired stimulationcommand, or other signals that affect operation of the signal processor1220 b.

In the example of FIG. 12B, the signal extraction module 1224 includes apair of tri-state buffers 1286 and 1288 in communication with signalsoutput from the signal generator 1212. The tri-state buffers 1286 and1288 are shown as having “enable” (ENB) signals provided by controller1226 in order to control operation of the tri-state buffers 1286 and1288 for extracting the signal from the signal generator 1212. Signalsfrom the signal generator 1212 and buffered by tri-state buffers 1286and 1288 are received by amplifier 1284, which can be configured toproduce a signal 1225 representative of the signal generated by thesignal generator 1212.

In some examples, communication of signals generated at the signalgenerator 1212 can be communicated to the signal processor 1220 b at aclock rate that is different from the clock rate of the signalsgenerated by the power signal generator 1211. For instance, in someembodiments, power signals from the power signal generator 1211 aretransmitted at approximately 30 kHz, which can be an efficient frequencyfor transmitting power. However, in some examples, the signals from thesignal generator 1212 are transmitted at a higher frequency than thesignal from the power signal generator 1211, for example, atapproximately 1 MHz. Such high frequency data transmission can be usefulfor faster data transfer than would be available at lower frequencies(e.g., the frequencies for transmitting the signal from the power signalgenerator 1211). Thus, in some embodiments, power and data can becommunicated from the implantable battery and/or communication module1210 b to the signal processor 1220 b via different communicationchannels at different frequencies.

Similar to the embodiment shown in FIG. 11B, in the illustrated exampleof FIG. 12B, the signal processor 1220 b includes a controller 1226 thatis in communication with the implantable battery and/or communicationmodule 1210 b. In some such embodiments, the controller 1226 in thesignal processor 1220 b is capable of monitoring the DC power 1223and/or the signal 1225 received from the implantable battery and/orcommunication module 1210 b. The controller 1126 can be configured toanalyze the received DC power 1223 and the signal 1225 and determinewhether or not the power and/or signal is sufficient. For example, thecontroller 1226 may determine that the signal processor 1220 b isreceiving insufficient DC power for stimulating a cochlear electrodeaccording to the signal processor 1220 b transfer function, or that datafrom the implantable battery and/or communication module 1210 b is notcommunicated at a desired rate. Thus, in some examples, the controller1226 of the signal processor 1220 b can communicate with the controller1214 of the implantable battery and/or communication module 1210 b andprovide feedback regarding the received communication. Based on thereceived feedback from the controller 1226 of the signal processor 1220b, the controller 1214 of the implantable battery and/or communicationmodule 1210 b can adjust various properties of the signals output by thepower signal generator 1211 and/or the signal generator 1212.

In the illustrated example of FIG. 12B, bidirectional communicationsignals 1251 b between the implantable battery and/or communicationmodule 1210 b and signal processor 1220 b comprises signals from theamplifiers 1294 and 1296 in one direction, and communication fromcontroller 1226 to controller 1214 in the other direction. It will beappreciated that a variety of communication protocols and techniques canbe used in establishing bidirectional communication signals 1251 bbetween the implantable battery and/or communication module 1210 b andsignal processor 1220 b.

For example, in some embodiments, the implantable battery and/orcommunication module 1210 b need not include amplifiers 1294 and 1296,and instead transmits a signal and not its inverse to the signalprocessor 1220 b. In other examples, the signal processor includesamplifiers similar to 1294 and 1296, and outputs a signal and itsinverse back to the implantable battery and/or communication module 1210b. Additionally or alternatively, in some embodiments, the signalgenerator 1212 can be integral with the controller 1214 and/or thesignal extraction module 1224 can be integral with controller 1226,wherein controllers 1214 and 1226 can be in bidirectional communicationvia signal generator 1212 and/or the signal extraction module 1224. Ingeneral, the implantable battery and/or communication module 1210 b andthe signal processor 1220 b can be in bidirectional communication forcommunicating data signals separate from the power signals provided bypower signal generator 1211.

As described, separate communication channels for power (e.g., 1250) anddata (e.g., 1251 b) can be used for providing both power and data fromthe implantable battery and/or communication module 1210 b and thesignal processor 1220 b. This can allow for separate data and powerclocking rates in order to improve the power transmission efficiency aswell as the data transmission efficiency and/or rate. Moreover, in someexamples, if the bidirectional communication (e.g., 1251 b) between theimplantable battery and/or communication module 1210 b and the signalprocessor 1220 b fails (e.g., due to component failure, connectionfailure, etc.), data for communication from the implantable batteryand/or communication module 1210 b can be encoded in the power signals(e.g., 1250) from the power signal generator 1211 and transmitted to thesignal processor 1220 b. Thus, similar to the embodiment described withrespect to FIG. 11B, both power and data can be transmitted via the samesignal.

In some examples, the signal extraction module 1224 can be configured toreceive data received from the power signal generator 1211, for example,via an actuatable switch that can be actuated upon detected failure ofcommunication 1251 b. In other examples, the signal extraction module1224 and/or the controller 1226 can generally monitor data from thepower signal generator 1211 and identify when signals received from thepower signal generator 1211 include data signals encoded into thereceived power signal in order to determine when to consider the powersignals to include data.

Accordingly, in some embodiments, the configuration of FIG. 12B can beimplemented to establish efficient, bidirectional communication betweenthe implantable battery and/or communication module 1210 b and thesignal processor 1220 b. Failure in bidirectional communication 1251 bcan be identified manually and/or automatically. Upon detection offailure in the bidirectional communication 1251 b, the controller 1214can encode data into the power signal output from the power signalgenerator 1211, and power and data can be combined into a single signalsuch as described with respect to FIG. 11B.

FIG. 12C is another alternative schematic diagram illustrating exemplaryelectrical communication between an implantable battery and/orcommunication module 1210 c and a signal processor 1220 c in a cochlearimplant system similar to that shown in FIG. 12A. Similar to theembodiment of FIG. 12B, in the illustrated embodiment of FIG. 12C, theimplantable battery and/or communication module 1210 c includes a powersignal generator 1211 configured to output a signal through a lead(e.g., 190) to the signal processor 1220 c. In some embodiments, thepower signal generator 1211 generates a digital signal (e.g., 1250) forcommunication to the signal processor 1220 c, for example, at a powerclock rate. The power signal generator 1211 and corresponding amplifiers1290, 1292, as well as rectifier circuit 1222, can operate similar todescribed with respect to FIG. 12B in order to extract DC power 1223and, in some examples, output power signals to further systemcomponents, such as stimulator 1230.

In the illustrated embodiment, the implantable battery and/orcommunication module 1210 c includes a signal generator 1213, which canbe capable of providing data signals to the signal processor. In someembodiments, the signal generator 1213 generates a digital signal forcommunication to the signal processor 1220 c. In some such embodiments,the digital signal (e.g., 1251 c) from the signal generator 1213 can becommunicated to the signal processor 1220 b at a data clock rate that isdifferent from the power clock rate. For instance, as describedelsewhere herein, in some configurations, power and data can becommunicated most effectively and/or efficiently at different clockrates. In an exemplary embodiment, the power clock rate is approximately30 kHz while the data clock rate is approximately 1 MHz. Utilizingdifferent and separately communicated power and data signals havingdifferent clock rates can increase the transfer efficiency of powerand/or data from the implantable battery and/or communication module1210 c to the signal processor 1220 c.

The embodiment of FIG. 12C includes a controller 1215 in communicationwith the power signal generator 1211 and the signal generator 1213. Insome examples, the controller 1215 is capable of adjusting communicationparameters such as the clock rate or content of the signal generator1213 and/or the power signal generator 1211. In an exemplary embodiment,the controller 1215 and/or the signal generator 1213 or power signalgenerator 1211 can communicate with, for example, a patient's externalprogrammer (e.g., as shown in FIG. 1). The controller 1215 and/or signalgenerator 1213 can be configured to communicate data to the signalprocessor 1220 c, such as updated firmware, signal processor 1220 ctransfer functions, or the like.

Similar to the example in FIG. 12B, in the example of FIG. 12C, thesignal generator 1213 outputs a data signal (e.g., 1251) to an amplifier1295 and an inverting amplifier 1297. In some examples, both amplifiersare unity gain amplifiers. In some examples, amplifiers 1295, 1297comprise tri-state buffers. In some examples comprising digital signals,the inverting amplifier 1297 can comprise a digital NOT gate. The outputfrom the amplifier 1295 and the inverting amplifier 1297 are generallyopposite one another and are directed to the signal processor 1220 c.

As described elsewhere herein, in some embodiments, the controller 1215and/or the signal generator 1213 is configured to encode data fortransmission via the amplifiers 1295 and 1297. The signal processor 1220c can include a signal extraction module 1234 configured to extract thedata from the signal(s) communicated to the signal processor 1220 c toproduce a signal for use by the signal processor 1220 c. In someexamples, the signal extraction module 1234 is capable of decoding thesignal that was encoded by the implantable battery and/or communicationmodule 1210 c. Additionally or alternatively, the signal extractionmodule 1234 can extract a signal resulting from the lead transferfunction. In various examples, the extracted signal can include, forexample, an updated transfer function for the signal processor 1220 c, adesired stimulation command, or other signals that affect operation ofthe signal processor 1220 c.

In the example of FIG. 12C, similar to signal extraction module 1224 inFIG. 12B, the signal extraction module 1234 includes a pair of tri-statebuffers 1287 and 1289 in communication with signals output from thesignal generator 1213. The tri-state buffers 1287 and 1289 are shown ashaving “enable” (ENB) signals provided by controller 1227 in order tocontrol operation of the tri-state buffers 1287 and 1289 for extractingthe signal from the signal generator 1213. Signals from the signalgenerator 1213 and buffered by tri-state buffers 1287 and 1289 arereceived by amplifier 1285, which can be configured to produce a signalrepresentative of the signal generated by the signal generator 1213.

As described elsewhere herein, in some examples, communication ofsignals generated at the signal generator 1213 can be communicated tothe signal processor 1220 c at a clock rate that is different from theclock rate of the signals generated by the power signal generator 1211.For instance, in some embodiments, power signals from the power signalgenerator 1211 are transmitted at approximately 30 kHz, which can be anefficient frequency for transmitting power. However, in some examples,the signals from the signal generator 1213 are transmitted at a higherfrequency than the signal from the power signal generator 1211, forexample, at approximately 1 MHz. Such high frequency data transmissioncan be useful for faster data transfer than would be available at lowerfrequencies (e.g., the frequencies for transmitting the signal from thepower signal generator 1211). Thus, in some embodiments, power and datacan be communicated from the implantable battery and/or communicationmodule 1210 c to the signal processor 1220 c via different communicationchannels at different frequencies.

In the illustrated example of FIG. 12C, the signal processor 1220 cincludes a signal generator 1217 and controller 1227 that is incommunication with the signal generator 1217. Similar to the operationof signal generator 1213 and amplifiers 1295 and 1299, the signalgenerator can be configured to produce output signals to buffers 1287and 1289, which can be configured to output signals to the implantablebattery and/or communication module 1210 c.

In some embodiments, the controller 1227 in the signal processor 1220 cis capable of monitoring the DC power 1223 and/or the signal receivedfrom the implantable battery and/or communication module 1210 c. Thecontroller 1126 can be configured to analyze the received DC power 1223and the signal and determine whether or not the power and/or signal issufficient. For example, the controller 1227 may determine that thesignal processor 1220 c is receiving insufficient DC power forstimulating a cochlear electrode according to the signal processor 1220c transfer function, or that data from the implantable battery and/orcommunication module 1210 c is not communicated at a desired rate. Thus,in some examples, the controller 1227 of the signal processor 1220 ccause the signal generator 1217 to generate communication signals tosend to implantable battery and/or communication module 1210 c. Suchsignals can be used to provide feedback regarding signals received bythe signal processor 1220 c, such as the DC power 1223.

In the example of FIG. 12C, amplifiers 1295 and 1297 are shown asincluding tri-state amplifiers (e.g., tri-state buffers) controllable bythe controller 1227. Similar to the configuration in the signalprocessor 1220 c, the implantable battery and/or communication module1210 c includes a signal extraction module 1235 configured to extractdata from the signal(s) communicated to the implantable battery and/orcommunication module 1210 c from signal generator 1217 of the signalprocessor 1220 c. The signal extraction module 1235 includes amplifiers1295 and 1297 (e.g., tri-state buffers) in communication with signalsoutput from the signal generator 1217. Signals from the signal generator1217 and received at amplifiers 1295 and 1297 are received by amplifier1299, which can be configured to produce a signal representative of thesignal generated by the signal generator 1217 to controller 1215 of theimplantable battery and/or communication module 1210. Thus, in someembodiments, the controller 1227 of the signal processor 1220 c isconfigured to communicate data back to the implantable battery and/orcommunication module 1210 a via buffers 1287 and 1289.

As described with respect to other embodiments, based on the receivedfeedback from the controller 1227 of the signal processor 1220 c, thecontroller 1215 of the implantable battery and/or communication module1210 c can adjust various properties of the signals output by the powersignal generator 1211 and/or the signal generator 1213.

Thus, in the illustrated example of FIG. 12C, bidirectionalcommunication signal 1251 between the implantable battery and/orcommunication module 1210 c and signal processor 1220 c includescommunication between different signal extraction modules 1235 and 1234.As shown, both the implantable battery and/or communication module 1210c and the signal processor 1220 c include a controller (1215, 1227) thatcommunicates with a signal generator (1213, 1217) for producing outputsignals. The signal generator (1213, 1217) outputs signals via tri-stateamplifiers, including one inverting amplifier (1297, 1289) forcommunication across bidirectional communication 1251 c for receipt bythe other signal extraction module (1234, 1235).

Thus, in some embodiments, bidirectional communication 1251 c betweenthe implantable battery and/or communication module 1210 c and thesignal processor 1220 c can be enabled by each of the implantablebattery and/or communication module and the signal processor receivingand transmitting data via approximately the same communication structureas the other. In some such examples, the implantable battery and/orcommunication module 1210 c and the signal processor 1220 c include dataextraction modules 1235 and 1234, respectively, configured both tooutput signals from a signal generator (e.g., via signal generator 1213or signal generator 1217) and receive and extract signals (e.g., viaamplifier 1285 and amplifier 1299).

In the example of FIG. 12C, amplifiers 1295 and 1297 comprise tri-stateamplifiers that selectively (e.g., via “enable” control from controller1215) output the signal from signal generator 1213, and amplifier 1297is shown as an inverting amplifier. As described, in some examples,amplifiers 1295 and 1297 comprise tri-state buffers. Similarly, oftri-state buffers 1287 and 1289 that selectively (e.g., via “enable”control from controller 1227) output the signal from signal generator1217, buffer 1289 is shown as an inverting amplifier. As describedelsewhere herein, communicating a signal and its inverse (e.g., via 1295and 1297) allows communication with no net charge flow between theimplantable battery and/or communication module 1210 c and the signalprocessor 1220 c. Thus, bidirectional communication between theimplantable battery and/or communication module 1210 c and the signalprocessor 1220 c can be performed without a net charge flow between thecomponents.

As described elsewhere herein, power from power generator 1211 and datafrom signal generator 1213 (and/or signal generator 1217) can becommunicated at different clocking rates to optimize power and datatransfer. In some examples, if data communication (e.g., viabidirectional communication 1251 c) fails, the controller 1215 can beconfigured to control power generator 1211 to provide both power anddata signals via amplifiers 1290 and 1292, for example, as describedwith respect to FIG. 11B.

Accordingly, in some embodiments, the configuration of FIG. 12C can beimplemented to establish efficient, bidirectional communication betweenthe implantable battery and/or communication module 1210 and the signalprocessor 1220. Failure in bidirectional communication 1251 can beidentified manually and/or automatically. Upon detection of failure inthe bidirectional communication 1251, the controller 1215 can encodedata into the power signal output from the power signal generator 1211,and power and data can be combined into a single signal such asdescribed with respect to FIG. 11B.

As discussed elsewhere herein, different safety standards can existregarding electrical communication within the patient's body. Forexample, safety standards can limit the amount of current that cansafely flow through a patient's body (particularly DC current). As shownin FIGS. 11B, 12B, and 12C, each of the illustrated communication pathsbetween the implantable battery and/or communication module and thesignal processor are coupled to output capacitors. The capacitorspositioned at the inputs and outputs of the implantable battery and/orcommunication module and the signal processor can substantially block DCcurrent from flowing therebetween while permitting communication of ACsignals.

As described elsewhere herein, in some embodiments, the datacommunicated between the implantable battery and/or communication moduleand the signal processor (e.g., from the signal generator) is encoded.In some such examples, the encoding can be performed according to aparticular data encoding method, such as an 8 b/10 b encoding scheme, toachieve DC balance in the communicated signal. For example, in someembodiments, data is encoded such that the numbers of high and low bitscommunicated between components at each clock signal meet certaincriteria to prevent a charge of a single polarity from building up onany of the capacitors. Such encoding can minimize the total charge thatflows between the implantable battery and/or communication module andthe signal processor during communication.

While described and illustrated as representing communication betweenthe implantable battery and/or communication module and the signalprocessor, it will be appreciated that communication configurations suchas shown in FIGS. 10, 11A, 11B, 12A, 12B, and 12C can be implementedbetween any pair of devices generally in communication with one another.For example, isolating circuitry (e.g., R_(Can)) can be included in anyof the system components (e.g., middle ear sensor, acoustic stimulator,electrical stimulator, etc.) to effectively isolate the ground signalsfrom each component from its respective can. Similarly, the exemplarycapacitive AC coupling with DC blocking capacitors and DC balancingencoding as described elsewhere herein can be incorporated as thecommunication interface between any two communicating components.

As described, data can be communicated from the implantable batteryand/or communication module to the signal processor for a variety ofreasons. In some examples, data is that communicated to the implantablebattery and/or communication module from an external component, such asa programmer as shown in FIG. 1. In an exemplary process, a programmer,such as a clinician's computer, can be used to communicate with apatient's fully implanted system via a communication configuration suchas shown in FIG. 11B, 12B, or 12C. For example, a programmer cancommunicate wirelessly (e.g., via Bluetooth or other appropriatecommunication technique) with the patient's implantable battery and/orcommunication module. Signals from the programmer can be sent from theimplantable battery and/or communication module to the signal processorvia the communication configurations of FIG. 11B, 12B, or 12C.

During such processes, a clinician can communicate with the signalprocessor, and, in some cases, with other components via the signalprocessor. For example, the clinician can cause the signal processor toactuate an electrical and/or an acoustic stimulator in various ways,such as using various electrical stimulation parameters, combinations ofactive contact electrodes, various acoustic stimulation parameters, andvarious combinations thereof. Varying the stimulation parameters in realtime can allow the clinician and patient to determine effectiveness ofdifferent stimulation techniques for the individual patient. Similarly,the clinician can communicate with the signal processor to updatetransfer function. For example, the clinician can repeatedly update thetransfer function signal processor while testing the efficacy of eachone on the individual patient. In some examples, combinations ofstimulation parameters and signal processor transfer functions can betested for customized system behavior for the individual patient.

In some embodiments, various internal properties of the system may betested. For instance, various impedance values, such as a sensorimpedance or a stimulator impedance can be tested such as described inU.S. Patent Publication No. 2015/0256945, entitled TRANSDUCER IMPEDANCEMEASUREMENT FOR HEARING AID, which is assigned to the assignee of theinstant application, the relevant portions of which are incorporated byreference herein.

Additionally or alternatively, various characteristics of individualleads can be analyzed. FIG. 12D is high-level schematic diagramillustrating exemplary electrical communication between an implantablebattery and/or communication module and a signal processor in a cochlearimplant system similar to that shown in FIG. 12A. In the simplifiedexample of FIG. 12D, conductors 1201, 1202, 1203, and 1204 extendbetween implantable battery and/or communication module 1210 d andsignal processor 1220 d. In some examples, such conductors are includedin a lead (e.g., lead 190) extending between the implantable batteryand/or communication module 1210 d and signal processor 1220 d. In theexample of FIG. 12D, implantable battery and/or communication module1210 d includes controller 1205 and signal processor 1220 d includescontroller 1206. Other internal components of the implantable batteryand/or communication module 1210 d and signal processor 1220 d are notshown, though various configurations are possible, such as shown in FIG.11B, 12B, or 12C.

In some embodiments, one or both of controllers 1205, 1206 can beconfigured to apply a test signal to one or more of conductors 1201,1202, 1203, 1204 in order to test one or more properties of suchconductors. In an exemplary test process, a controller (e.g., 1205) candrive a signal (e.g., a sine wave or other shaped wave) across aconductor (e.g., 1201) and measure the sent current and the voltage atwhich the current is sent. From this information, the controller candetermine conductor impedance, including integrity of the conductor(e.g., whether or not the conductor is broken). Similarly, a controllercan be configured to ground a second conductor (e.g., 1202) whiledriving the test signal across a test conductor (e.g., 1201) in order tomeasure one or more electrical parameters between the two conductors(e.g., capacitance, impedance, etc.).

During exemplary operation, a controller can be configured to apply atest signal to a first conductor (e.g., 1201) and ground a secondconductor (e.g., 1202). The controller can be configured to apply a testsignal at a plurality of frequencies (e.g., perform a frequency sweep)and measure impedance vs. frequency between the first conductor and thesecond, grounded conductor. In various examples, a controller can beconfigured to perform such tests using any two conductors 1201, 1202,1203, 1204, to test for baseline values (e.g., when the system is in aknown working condition) or to test for expected values (e.g., tocompare to an established baseline). In different embodiments, thecontroller in the implantable battery and/or communication module 1210 d(controller 1205) and/or the controller in the signal processor 1220 d(controller 1206) can perform the grounding of one or more conductorsand/or apply the test signal to one or more conductors.

In some embodiments, such test processes can be performed automatically,for example, according to a programmed schedule. Additionally oralternatively, such test processes can be initiated manually, forexample, by a wearer or a clinician, via an external device such as viaa programmer (e.g., 100) or charger (e.g., 102). The results of suchprocesses can be stored in an internal memory for later access andanalysis, and/or can output to an external device for viewing. In someexamples, results and/or a warning can be output to an external deviceautomatically in the event that one or more results deviatessufficiently from a baseline value. In various examples, sufficientvariation from the baseline for triggering an output can be based on apercent variation from the baseline (e.g., greater than 1% deviationfrom be baseline, greater than 5% deviation, greater than 10% deviation,etc.). Additionally or alternatively, sufficient variation an includevarying a certain number of standard deviations from the baseline (e.g.,greater than one standard deviation, two standard deviations, etc.). Invarious embodiments, the amount of variation that triggers outputtingthe results and/or a warning is adjustable. Additionally oralternatively, such an amount can vary between different measurements.

In some embodiments, one or more actions may be performed in response tothe results of such an analysis. For instance, in an exemplaryembodiment described with respect to FIG. 12B, if a test reveals anunexpected impedance on one of the signal conductors (e.g., fromamplifier 1294 or inverting amplifier 1296), such as an open circuit,the controller 1214 may be configured to change operation of the system.For instance, controller 1214 can be configured to adjust the outputfrom power generator 1211 in order to provide both power and datasignals from the power generator 1211, such as described with respect tothe configuration in FIG. 11B. In some examples, the controller 1214 canbe configured to transmit a signal to an external device signaling sucha change in operation and/or alerting a wearer and/or clinician that oneor more conductors may be damaged or otherwise not operational.

While shown in several embodiments (e.g., FIGS. 1, 9, 11A, 12A) as beingseparate components connected by a lead (e.g., lead 180), in someexamples, the processor (e.g., 120) and the stimulator (e.g., 130) canbe integrated into a single component, for example, within ahermetically sealed housing. FIG. 13A shows an exemplary schematicillustration of processor and stimulator combined into a single housing.In the example of FIG. 13A, the processor/stimulator 1320 receivessignal inputs from the sensor (e.g., a middle ear sensor) via lead 1370and power from a battery (e.g., the implantable battery and/orcommunication module) via lead 1390. The processor/stimulator 1320 caninclude headers 1322, 1324 for receiving leads 1370, 1390, respectively.

The processor/stimulator 1320 can be configured to receive an inputsignal from the sensor, process the received input signal according to atransfer function, and output a stimulation signal via electrode 1326.Electrode 1326 can include one or more contact electrodes (e.g., 1328)in contact with a wearer's cochlear tissue to provide electricalstimulation thereto, for example, as described with respect to FIG. 10B.

The processor/stimulator 1320 of FIG. 13 includes a return electrode1330 for providing a return path (e.g., 1332) for stimulation signalsemitted from electrode 1326. The return electrode 1330 can beelectrically coupled to a ground portion of circuitry within theprocessor/stimulator 1320 to complete a circuit comprising circuitrywithin the processor/stimulator 1320, the electrode 1326, the wearer'scochlear tissue, and ground. In some examples, the return electrode 1330comprises an electrically conductive material in electricalcommunication with circuitry inside the processor/stimulator 1320, whilethe rest of the housing of the processor/stimulator 1320 is generallynot electrically coupled to internal circuitry.

In some embodiments, the return electrode 1330 and the housing of theprocessor/stimulator 1320 comprise electrically conductive materials.For instance, in some examples, the housing comprises titanium while thereturn electrode 1330 comprises platinum or a platinum alloy. Header1324 can generally include a non-conductive biocompatible material, suchas a biocompatible polymer. The non-conductive header 1324 can provideisolation between the return electrode 1330 and the conductive housingof the processor/stimulator 1320.

While shown in FIG. 13A as being positioned in the power header 1324 ofthe processor/stimulator 1320, in general, the return electrode 1330 canbe positioned anywhere on the exterior surface of theprocessor/stimulator 1320. In some examples, one or more redundantreturn electrodes can be included, for example, at or near the interfaceof the housing and the electrode 1326. In some examples, a returnelectrode can be positioned on a proximal end of the electrode 1326itself. In some embodiments having a plurality of return electrodes(e.g., return electrode 1330 and a return electrode on the proximal endof electrode 1326), a switch can be used to select which returnelectrode is used. Additionally or alternatively, a plurality of returnelectrodes can be used simultaneously.

FIG. 13B shows a simplified cross-sectional view of theprocessor/stimulator shown in FIG. 13A taken along lines B-B. As shownin FIG. 13B, processor/stimulator 1320 includes a housing having a firstside 1319 and a second side 1321 and a return electrode 1330 embedded inthe housing. Return electrode 1330 can comprise a conductive materialsuitable for contact with a wearer's tissue, such as platinum. In theillustrated example, the return electrode 1330 wraps around to bothsides of the housing of the processor/stimulator 1320 so that the returnelectrode 1330 is coupled to the outer surface of the housing on thefirst side 1319 and the second side 1321.

This can facilitate implanting onto either side of a wearer's anatomy,since in some cases, only one side of the processor/stimulatorelectrically contacts conductive tissue of the wearer while the otherside contacts, for instance, the skull of the wearer, and does noteasily provide the return path (e.g., 1332). Thus, a singleprocessor/stimulator design can be implanted in either side of awearer's anatomy while providing an adequate return path via a returnelectrode 1330.

In various examples, the return electrode 1330 can extend around aperimeter edge of the processor/stimulator 1320, as shown in FIG. 13B.In other examples, the return electrode 1330 can include sections oneither side of the housing and can be connected to one anotherinternally within the housing rather than via a wrap-around contact.Additionally, while shown as being embedded in the housing of theprocessor/stimulator 1320, in some examples, return electrode 1330 canprotrude outwardly from the housing. Return electrode 1330 can generallybe any of a variety of shapes and sizes while including an electricalcontact section on opposing sides of the housing to provide usability oneither side of a wearer's anatomy. In other embodiments, returnelectrode can be positioned only one side of the housing for acustomized right-side or left-side implementation.

As described elsewhere herein, in various embodiments, the processorgenerally receives an input signal, processes the signal, and generatesa stimulation signal, which can be applied via an integrated stimulator(e.g., via a processor/stimulator such as in FIGS. 13A and 13B) or aseparate stimulator in communication with the processor (e.g., as shownin FIGS. 1 and 9). In some such embodiments, the input signal receivedvia the signal processor is generated by an implantable sensor, such asa middle ear sensor (e.g., as described with respect to FIGS. 4 and 5).

However, such sensors often measure or otherwise receive some stimulusthat is converted into an output that is read and processed by thesignal processor. For example, some middle ear sensors may produce adifferent output signal for a given stimulus depending on a variety offactors, such as variability in a wearer's inner-ear anatomy and motion.Thus, the output of a sensor for a given input may be not predictablewhile designing a system, especially across a range of frequencies.

FIG. 14A is a schematic diagram showing an exemplary signal processingconfiguration for normalizing a stimulus signal and adapting tovariability in a sensor frequency response. FIG. 14B shows an exemplarygain vs. frequency response curve for signals at various stages in theprocessing configuration. “Gain” associated with a particular frequency,as used with respect to FIG. 14B, refers to a relationship (e.g., aratio) between the magnitude of an input stimulus received by the sensorand processor and the magnitude of the resulting signal at variousstages of processing. In the illustrated example, theprocessor/stimulator 1400 receives an input signal 1405 from the sensor.

As shown in FIG. 14B, the gain is very uneven over the distribution offrequencies shown in the plot. For instance, according to theillustrated example, a stimulus signal received at the sensor at 1 kHzwill result in a much larger magnitude in signal 1405 compared to astimulus signal of the same magnitude received at the sensor at 10 kHz.Such a discrepancy in frequency response can make signal processingdifficult. Moreover, such frequency response in general may vary fromperson to person, or over the course of a wearer's lifetime due tophysical movement of a sensor or anatomical changes.

The input signal 1405 undergoes analog processing 1410 to produce ananalog processed signal 1415. As shown in FIG. 14B, the analogprocessing step 1410 improves the consistency of the gain across therange of frequencies, as the analog processed signal 1415 provides aflatter frequency response curve than does the input signal 1405. Insome embodiments, the analog processing can include one or more filterand/or amplifiers generally configured to flatten out the frequencyresponse curve as shown in FIG. 14B. In some examples, the analogprocessing components 1410 within the processor/stimulator 1400 can besubstantially the same across various implantable systems in order toprovide a first order correction of the frequency response. In otherexamples, an analog processing configuration 1410 can be customized tothe wearer, for example, based on known anatomical features,measurements, analysis, or the like.

The analog processed signal 1415 undergoes a digital processing step1420 to produce a digitally processed signal 1425. As shown in FIG. 14B,the digital processing step 1420 further improves the consistency of thegain across the range of frequencies, as the digitally processed signal1425 provides a flatter frequency response curve than does the analogprocessed signal 1415. In some embodiments, the digital processing 1420can be configured to substantially flatten the frequency response tocorrect remaining frequency response inconsistencies in the analogprocessed signal 1415. For instance, in some embodiments, after digitalprocessing 1420, a stimulus signal of a given magnitude at a firstfrequency and a second frequency will result in a digitally processedsignal 1425 having the same magnitude at the first and the secondfrequencies. Thus, the digitally processed signal 1425 corresponds to anormalized stimulus signal, reducing or eliminating the variability thatcomes with different wearer anatomies and wearer motion and/or changesover time. Having a normalized frequency response across large frequencyranges can simplify assessment of the efficacy of the implanted system,programming a signal processor transfer function, assessing systemoperation, and the like. In some examples, a flat frequency response canenable the system to present an electrical stimulus to the wearer atappropriate intensity levels, for example, with respect to receivedexternal acoustic stimuli, independent of the frequency content of theexternal acoustic stimuli.

In some embodiments, the digital processing 1420 can be customized via acalibration process after the system has been implanted. In an exemplarycalibration process, a clinician or other user may provide a series ofstimulus signals, for instance, at a plurality of frequencies and havinglike amplitudes, to be “picked up” by the sensor, which generates aninput signal 1405 for each received signal. The clinician or other usermay then sample the resulting analog processed signal 1415 and/or aninitial digitally processed signal 1425 at the plurality of frequenciesto determine the remaining non-uniformity in gain across the frequencysweep. The digital processing 1420 can be either established or updatedto compensate for non-uniformities in order to establish a substantiallyflat frequency response curve in the digitally processed signal 1425. Insome examples, a plurality of signals having different frequencies areprovided in sequence and a magnitude response (e.g., gain) at eachfrequency is determined. After determining such a magnitude response,the digital processing stage 1420 can be updated based on the responsevs. frequency relationship in order to flatten the frequency responsecurve.

In an alternate process, a white noise signal can be provided to be“picked up” by the sensor. A transform (e.g., a Fast Fourier Transform,or FFT) of the signal can be performed in order to extract the frequencycontent of the signal. The extracted frequency content can used todetermine a magnitude response at each frequency and the digitalprocessing 1420 can be updated to flatten the frequency response similarto described above.

In the illustrated example of FIG. 14A, the digitally processed signal1425 (e.g., having a uniform gain across a frequency range with respectto input signals received from the sensor) is processed according to thesignal processor transfer function 1430 to generate a stimulation signal1435. Stimulation signal 1435 can be received by the stimulator 1440,which can apply an electrical signal 1445 to the electrode such asdescribed elsewhere herein.

In some examples, the digital processing step 1420 to provide a uniformfrequency response can be incorporated into the transfer function 1430wherein the analog processed signal 1415 is digitally processed to bothflatten the frequency response and to generate a stimulation signal(e.g., 1435) according to a programmed transfer function. Additionallyor alternatively, as described elsewhere herein, in some examples,stimulator 1440 can be located external to the processor rather thanbeing combined as a single processor/stimulator component 1400.

As described elsewhere herein, while many examples show a middle earsensor being in communication with an implanted signal processor, invarious embodiments, one or more additional or alternative input sourcescan be included. For instance, in some embodiments, a microphone can beimplanted under a user's skin and can be placed in communication withthe signal processor (e.g., via a detachable connector such as 171). Thesignal processor can receive input signals from the implanted microphoneand provide signals to the stimulator based on the received input signaland the signal processor transfer function.

Additionally or alternatively, one or more system components can beconfigured to receive broadcast signals for converting into stimulationsignals. FIG. 15 is a schematic system diagram showing an implantablesystem configured to receive broadcast signals from a broadcast device.As shown in the example of FIG. 15, a broadcast source 1550 broadcasts asignal via communication link 1560. The communication link 1560 caninclude communication via a variety of communication protocols, such asWi-Fi, Bluetooth, or other known data transmission protocols. Broadcastsource 1550 can include any of a variety of components, such as a mediasource (e.g., television, radio, etc.), communication device (e.g.,telephone, smartphone, etc.), a telecoil or other broadcast system(e.g., at a live performance), or any other source of audio signals thatcan be transmitted to an implanted system or to an external component ofan implanted system (e.g., a system programmer, etc.).

An implantable system including a programmer 1500, an implantablebattery and/or communication module 1510, a signal processor 1520, and astimulator 1530 can generally receive the data from the broadcast source1550 via communication link 1560. In various embodiments, any number ofcomponents in the implantable system can include a receiving device,such as a telecoil, configured to receive broadcast signals for eventualconversion into stimulation signals.

For instance, in some embodiments, programmer 1500 can include atelecoil relay configured to receive broadcast telecoil signals from abroadcast source 1550. The programmer can be configured to subsequentlycommunicate a signal representative of the received broadcast signal tothe implantable battery and/or communication module 1510 and/or thesignal processor 1520, e.g., via a Bluetooth communication. If thecommunication is received from the programmer 1500 via the implantablebattery and/or communication module 1510, the implantable battery and/orcommunication module 1510 can communicate the signal to the signalprocessor, for example, as described in any of FIG. 11A, 11B, 12A, or12C.

In some such embodiments, the signal processor 1520 can be configured toreceive such signals from the implantable battery and/or communicationmodule 1510 and output stimulation signals to the stimulator 1530 basedon the received signals and the signal processor transfer function. Inother examples, the signal processor 1520 can include a telecoil relayor other device capable of receiving broadcast signals from thebroadcast source 1550. In some such embodiments, the signal processor1520 processes the received signals according to the signal processortransfer function and outputs stimulations signals to the stimulator1530.

In some embodiments, the signal processor 1520 can be in communicationwith a plurality of input sources, such as, for example, a combinationof an implanted microphone, a middle ear sensor, and a broadcast source1550 (e.g., via the implantable battery and/or communication module1510). In some such examples, the signal processor can be programmedwith a plurality of transfer functions, each according to respectiveinput sources. In such embodiments, the signal processor can identifywhich one or more input sources are providing input signals and processeach such input signal according to the transfer function associatedwith its corresponding input source.

In some examples, a signal processor 1520 receiving a plurality of inputsignals from a corresponding plurality of input sources effectivelycombines the signals when producing a stimulation signal to thestimulator 1530. That is, in some embodiments, input sources arecombined to form the stimulation signal from the signal processor 1520.In some such examples, a user may be able to mix the various receivedinput signals in any way desired. For example, a user may choose toblend a variety of different input streams, such as an input from amiddle ear sensor or other implanted device, a signal received from anexternal device (e.g., a telecoil relay, a Bluetooth connection such asto a smartphone, etc.), and the like. In an exemplary configuration, auser may elect to equally blend two input sources such that thestimulation signal is based 50% on a first input source and 50% on asecond input source.

Additionally or alternatively, a user may elect to effectively “mute”one or more input sources so that the signal processor 1520 outputsstimulations signals based on input signals received from unmutedsources. Similarly, a user may be able to select a single source fromwhich to process received input signals. For example, in someembodiments, a user may select to have signals received from broadcastsource 1550 processed and converted into stimulation signals whilehaving signals received from, for example, a middle ear sensor,disregarded.

In some examples, direct communication with the signal processor can beused to test the efficacy of a given signal processor transfer functionand associated stimulation (e.g., acoustic or electrical) parameters.For example, the programmer can be used to disable input signals from amiddle ear sensor or other input source and provide a customized signalto the signal processor to simulate a signal from the input source. Thesignal processor processes the received signal according to its transferfunction and actuates the electrical stimulator and/or the acousticstimulator accordingly. The processor can be used to test a variety ofcustomized “sounds” to determine the efficacy of the signal processortransfer function for the given patient for each “sound.”

FIG. 16 is a process flow diagram illustrating an exemplary process forestablishing a preferred transfer function for a patient. The method caninclude connecting an external programmer to the implantable batteryand/or communication module (step 1650). Connecting can include, forexample, establishing a wireless connection (e.g., Bluetoothcommunication) between an external programmer and the implantablebattery and/or communication module. The external programmer can includeany variety of components capable of providing programming instructionsto the implantable battery and/or communication module, such as acomputer, smartphone, tablet, or the like.

Once communication is established, if there is no signal processortransfer function active (step 1652), a signal processor transferfunction can be established (step 1654). If a transfer function isalready active, or after one has been established (step 1654), theprogrammer can be used to input one or more simulated “sounds” to thesignal processor. Such “sounds” can be received and treated by thesignal processor as if they were received from an input source such as amiddle ear sensor. The “sounds” can be, for example, computer-generatedsignals designed to simulate various input signals, such as a range offrequencies, phonetic sounds, or other distinguishable soundcharacteristics.

The process can further include testing the efficacy of the signalprocessor transfer function (step 1658). This can include, for example,determining how well the patient responds to each sound provided a givensignal processor transfer function. In some examples, this can includerating the transfer function under test for each of the “sounds” anddetermining an aggregate score for the transfer function based on thescore(s) associated with the one or more “sounds.”

After testing the efficacy of the signal processor transfer function, ifnot all desired transfer functions have been tested (step 1660), thesignal transfer function can be updated (step 1654). The one or moresimulated “sounds” can be input to the signal processor (step 1656) andprocessed according to the updated transfer function, and the efficacyof the updated transfer function can be tested (step 1658). Once alldesired transfer functions have been tested (step 1660), a signalprocessor transfer function for the user can be created or selected andimplemented for the patient (step 1662). In some examples, a besttransfer function of the tested transfer functions is selected based ona user preference, a highest score, or other metric. In other examples,composite results from the tested transfer functions can be combined tocreate a customized transfer function for the patient.

In other examples, rather than continually updating the signal processortransfer function, simulated “sounds” can be pre-processed outside ofthe signal processor, for example, on site with a clinician oraudiologist. For instance, in an exemplary process, one or moresimulated sounds can be pre-processed using processing software toestablish simulated stimulation signals that would result from aparticular input signal being processed via a particular transferfunction. In some examples, such signals can be transferred to, forexample, the signal processor for directly applying stimulation signalsto the wearer.

Communication to the stimulator can be performed, for example, directlyfrom various system components, such as a programmer. In other examples,such communication can be performed via the implantable battery and/orcommunication module and signal processor. For instance, in an exemplaryembodiment, pre-processed signals can be communicated to the implantablebattery and/or communication module via a wireless (e.g., Bluetooth)communication. The implantable battery and/or communication module cancommunicate the pre-processed signals to the signal processor, which canbe configured with a unity transfer function. Thus, the signal processormerely passes the pre-processed signals on to the stimulator forperforming stimulation.

FIG. 17 is a process flow diagram showing an exemplary method of testingthe efficacy of one or more sounds using one or more transfer functionsvia pre-processed signals. In the method of FIG. 17, a sound can beloaded (step 1750), for example, into an application or processingsoftware capable of processing the received sound. In some examples, thesound can be a simulated sound, such as a computer-generated signalrepresenting a desired sound. In other examples, the sound can include arecording of an actual sound, such as a person's voice or otherstimulus. The loaded sound can be pre-processed according to a transferfunction to generate a stimulation signal (step 1752). Thepre-processing can be performed, for example, on a stand-alone workstation, a system programmer, or the like.

The method of FIG. 17 further comprises the step of applying thestimulation signal from the pre-processed sound to the stimulator of theimplanted system (step 1754). As described elsewhere herein, suchcommunication of the stimulation signal to the stimulator can beperformed in a variety of ways, such as directly to the stimulator(e.g., from an external workstation, the user's programmer, etc.) orthrough the signal processor.

Upon applying the stimulation signal (step 1754), the method can furtherinclude the step of testing the efficacy of the stimulation signal (step1756). This can include, for example, testing a user's comprehension ofthe initial sound from the received stimulation signal, receiving arating score from the user, or any other appropriate way of resting theefficacy of the stimulation signal. Since the stimulation signal appliedin step 1754 is based on the sound and the transfer function used forpre-processing, testing the efficacy of the stimulation signal issimilar to testing the efficacy of the transfer function for the givensound.

After testing the efficacy of the stimulation signal, it can bedetermined whether all simulation transfer functions have been testedfor the given sound (step 1758). If not, the method can include the stepof establishing or updating a simulated transfer function (step 1760),and repeating the steps of pre-processing the sound to establish astimulation signal (step 1752), applying the stimulation signal (step1754), and testing the efficacy of the stimulation signal (step 1756)all according to the updated transfer function. Thus, a given sound canbe processed according to a plurality of transfer functions, and aplurality of corresponding stimulation signals can be tested withrespect to a given user. If all simulation transfer functions have beentested at step 1758, the process can include establishing a preferredprocessing for the sound (step 1762).

In some examples, the process of FIG. 17 can be performed in real time.For instance, in some embodiments, a device in communication with thestimulator in an implanted system (e.g., directly via wirelesscommunication with the stimulator or indirectly via signal processor)can cycle through various simulated transfer functions whilepre-processing sound signals prior to communicating them to the user'ssystem. In some such examples, after establishing a preferred processingtechnique (e.g., simulated transfer function) for a given sound (e.g.,in step 1762), the user's signal processor transfer function can beupdated to reflect the preferred transfer function for the given sound.

Additionally or alternatively, the process of FIG. 17 can be repeatedfor a plurality of different sounds. In some embodiments, a plurality ofsounds can be pre-processed according to a plurality of differentsimulated transfer functions, and the resulting generated stimulationsignals can be stored in a database. A testing device, such as aworkstation, programmer, etc., can be used to carry out the method ofFIG. 17 while using the database of stimulations signals to test theefficacy of various transfer functions with respect to various soundsfor a user.

In some examples, such a database can be used to fit a user with aparticular implant system. For example, stimulation signals generated bypre-processing a plurality of sounds can be communicated to theimplanted stimulator of a user having an implanted stimulator andcochlear electrode in order to test the efficacy of the transferfunction simulated in the pre-processing. In various examples, aplurality generated stimulation signals associated with a given soundcan be applied to the stimulator until a preferred simulated transferfunction is established. In other examples, generated stimulationsignals representative of a plurality of sounds can be established foreach of a plurality of transfer functions, such that each transferfunction can be tested on a user for a plurality of sounds prior totesting another transfer function.

FIG. 18 is a schematic representation of an exemplary database ofpre-processed sound signals. As shown, the database is represented as atable having n rows corresponding to different sounds (sound 1, sound 2,. . . , sound n) and m columns corresponding to different simulatedtransfer functions (simulated transfer function 1, simulated transferfunction 2, . . . , simulated transfer function m). As shown, at theintersection of each row (i) and each column (j), pre-processing a soundi with a simulated transfer function j results in stimulation signal(i,j). In some embodiments, a table such of stimulation signalsgenerated from pre-processed sounds such as shown in FIG. 18 can bestored in a database of pre-processed sound signals for device fittingfor a user.

As described elsewhere herein, in various fitting processes, a sound maybe selected from database (e.g., sound 1), and a plurality of differentstimulation signals (e.g., stimulation signal (1,1), stimulation signal(1,2), . . . , stimulation signal (1,m)) can be communicated to animplanted stimulator. Such stimulation signals generally correspond tothe result of the sound (e.g., sound 1) being pre-processed according tovarious simulated transfer functions (1-m). As described with respect toFIG. 17, a preferred stimulation signal (and thus, a preferredcorresponding simulated transfer function) can be established for thegiven sound (e.g., sound 1). A similar process can be repeated for eachsound in the database. In various examples, one or more signal processortransfer functions can be communicated to the signal processor based onthe determined preferred simulated transfer function(s). For instance,in some example, the simulated transfer function that was preferredamong the most sounds may be implemented as the signal processortransfer function. In other embodiments, the signal processor includes aplurality of transfer functions, and can apply different transferfunctions to different detected sounds depending on the preferredtransfer function for each sound.

In other exemplary fitting processes, a plurality of stimulation signals(e.g., stimulation signal (1,1), stimulation signal (2,1), . . . ,stimulation signal (n,1)) corresponding to a single simulated transferfunction (e.g., simulated transfer function 1) can be applied to astimulator. Such stimulation signals correspond to a plurality of soundsthat are pre-processed according to the single simulated transferfunction. This can be used to test the efficacy of the selected transferfunction. The process can be repeated for a plurality of simulatedtransfer functions (e.g., 2-m) in order to determine a best transferfunction across a variety of sounds (e.g., sounds 1-n).

In general, a database of stimulation signals generated bypre-processing sound signals via various transfer functions such asshown in FIG. 18 can be useful for expediting the testing of suchtransfer functions for a particular user. Pre-processing such soundsallows for the processing to be done, for example, in a lab or on aworkstation prior to any fitting process and allows for efficientapplication of stimulation signals corresponding to different transferfunctions to a user's stimulator without requiring updates of the signalprocessor. Additionally, such pre-processing can allow for more advancedor computationally demanding processing techniques to be tested forefficacy even if such processing techniques may not yet be effectivelyimplemented by an implanted signal processor (e.g., due to varioushardware limitations). Testing the efficacy of such processingtechniques can motivate evolution of processing methodologies andhardware capability, for example, in an effort to employ more complexprocessing techniques in the future.

Various features and functions of implantable systems have beendescribed herein. As described, in various embodiments, systemoperation(s) can be adjusted based on communication with the implantedsystem from components located outside of the body while the systemremains implanted. In some embodiments, the system may include anynumber of external components capable of interfacing with the system ina variety of ways.

FIG. 19 is a schematic diagram illustrating possible communicationbetween a variety of system components according to some embodiments ofa fully implantable system. In the illustrated embodiment, implantedcomponents (outlined in broken line) of a system include an implantablebattery and/or communication module 1910, a signal processor 1920, and astimulator 1930. Such implanted components can operate according tovarious examples as described herein in order to effectively stimulate auser (e.g., via electrical and/or acoustic stimulation) in response toreceived input signals.

The schematic illustration of FIG. 19 includes a plurality of externaldevices capable of wirelessly interfacing with one or more of theimplanted components, for example, via communication link 1925. Suchdevices can include a programmer 1900, a charger 1902, asmartphone/tablet 1904, a smartwatch or other wearable technology 1906,and a fob 1908. In some examples, such components can communicate withone or more implantable components via one or more communicationprotocols via wireless communication link 1925, such as Bluetooth,Zigbee, or other appropriate protocols. In various embodiments,different external devices are capable of performing one or morefunctions associated with system operation. In some such embodiments,each external device is capable of performing the same functions as theothers. In other examples, some external devices are capable ofperforming more functions than others.

For example, a programmer 1900 can be capable of interfacing wirelesslywith one or more implantable components in order to control a variety ofoperating parameters of the implanted system. For example, in someembodiments, programmer 1900 can be configured to adjust a signalprocessor transfer function or select an operating profile (e.g.,associated with a particular signal processor transfer functionaccording to a particular user, environment, etc.). In some examples,the programmer 1900 can be used to establish user profiles, such aspreferred signal processor transfer functions, as described elsewhereherein. The programmer 1900 can additionally or alternatively be used toturn the system on or off, adjust the volume of the system, receive andstream input data to the system (e.g., the implantable battery and/orcommunication module 1910). In some embodiments, the programmer 1900includes a display for displaying various information to the user. Forexample, the display can be used to indicate a mode of operation (e.g.,a loaded user profile), a remaining power level, or the like. In somesuch embodiments, the display can function as a user interface by whicha user can adjust one or more parameters, such as volume, profile, inputsource, input mix, and the like.

In some embodiments, a charger 1902 can be used to charge one or moreinternal batteries or other power supplies within the system, such as inthe implantable battery and/or communication module 1910. In someexamples, the charger 1902 can include the same functionality as theprogrammer 1900, including, for instance, a display and/or userinterface. In some such embodiments, the programmer 1900 and the charger1902 can be integrated into a single device.

In some embodiments, various external devices such as a smartphone ortablet 1904 can include an application (“app”) that can be used tointerface with the implanted system. For example, in some embodiments, auser may communicate (e.g., via link 1925) with the system via thesmartphone or tablet 1904 in order to adjust certain operating factorsof the system using a predefined app to provide an interface (e.g., avisual interface via a display integrated into the external device). Theapp can assist the user in adjusting various parameters, such as volume,operating profile, on/off, or the like. In some examples, thesmartphone/tablet 1904 can be used to stream input signals to theimplanted system, such as media or communication playing on thesmartphone/tablet 1904.

In some systems, a smartwatch or other wearable technology 1906 caninteract with the system in a similar way as the smartphone/tablet 1904.For example, the smartwatch or other wearable technology 1906 caninclude an app similar to that operable on the smartphone/tablet tocontrol operation of various aspects of the implanted system, such asvolume control, on/off control, etc.

In some embodiments, the fob 1908 can be used to perform basic functionwith respect to the implanted system. For instance, in some embodiments,a fob 1908 can be used to load/implement a particular operating profileassociated with the fob 1908. Additionally or alternatively, the fob1908 can function similar to the shut-off controller 104 of FIG. 1 andcan be used to quickly disable and/or mute the system. As describedelsewhere herein, in some examples, the same device used to disableand/or mute the system (e.g., fob 1908) can be used to enable and/orunmute the system.

The schematic diagram of FIG. 19 further includes a broadcast source1950 configured to broadcast signals 1960 that are receivable via one ormore external devices and/or one or more implanted system components.Similar to the broadcast source 1550 in FIG. 15, broadcast source 1950can be configured to emit signals that can be turned into stimulationsignals for application by stimulator 1930. Broadcast signals 1960 caninclude, for example, telecoil signals, Bluetooth signals, or the like.In various embodiments, one or more external devices, such as aprogrammer 1900, charger 1902, smartphone/tablet 1904,smartwatch/wearable device 1906, and/or fob 1908 can include a component(e.g., a telecoil relay) capable of receiving broadcast signal 1960. Theexternal device(s) can be further configured to communicate a signal toone or more implanted components representative of the receivedbroadcast signal 1960 for applying stimulation to the patient based onthe broadcast signal 1960.

Additionally or alternatively, in some embodiments, one or moreimplanted system components, such as an implantable battery and/orcommunication module 1910, a signal processor 1920, and/or a stimulator1930 can be configured to receive broadcast signals 1960. Suchcomponent(s) can be used to generate stimulation signals for applying toa user via stimulator 1930 according to the received broadcast signals1960.

As described, in some embodiments, various devices can communicate withcomponents in an implanted system via wireless communication protocolssuch as Bluetooth. Various data and signals can be communicatedwirelessly, including control signals and streaming audio. However, insome cases, such wireless communication should be made secure so that asystem only communicates with those devices desired by the wearer. Thiscan prevent unwanted signals from being broadcast to an implanted deviceand/or unauthorized access to one or more adjustable device settings.

In some embodiments, one or more implanted system components comprises anear field communication component configured to facilitatecommunication between the system and an external device only whenbrought into very close proximity to the near field communicationcomponent. In some such examples, once near-field communication isestablished, the pairing for longer-range wireless communication (e.g.,Bluetooth) can be established. For instance, in an exemplary embodiment,a charger and an implantable battery and/or communication module caneach include near field communication components for establishing asecure, near field communication and subsequently pairing to each otherfor additional wireless communication.

FIG. 20 is a schematic diagram showing establishing a secure wirelessconnection between various components in an implantable system. In theillustrated example, a charger 2010 is configured to communicate withimplantable battery and/or communication module 2020. Charger 2010includes a wireless communication component 2016, such as a Bluetoothlink, that can facilitate communication between the charger 2010 andother devices. Charger 2010 further includes a near field communicationcomponent 2012, such as a coil, and a processor/memory component 2014that can receive signals from and communicate signals to near fieldcommunication component 2012 and/or wireless communication component2016.

Implantable battery and/or communication module 2020 includes a wirelesscommunication component 2026, such as a Bluetooth link, that canfacilitate communication between the charger 2010 and other devices.Implantable battery and/or communication module 2020 further includes anear field communication component 2022, such as a coil, and aprocessor/memory component 2024 that can receive signals from andcommunicate signals to near field communication component 2022 and/orwireless communication component 2026.

In some embodiments, the near field communication components 2012 and2022 comprise coils capable of establishing near field wirelesscommunication therebetween. In some embodiments, the coils can also beused to transfer power between a power source 2018 of the charger 2010to a power source 2028 of the implantable battery and/or communicationmodule 2020, for example, to charge the power source 2028 in theimplanted system for continued use. In various embodiments, power source2018 and/or power source 2028 can include one or more batteries,capacitors (e.g., supercapacitors), and/or other power storage devicesthat can store and provide electrical energy to other components. Insome embodiments, power source 2018 in charger 2010 can include anexternal or removable power source, such as a removable or replaceablebattery and/or a power cord that can be plugged into a standard wallreceptacle.

In some examples, implantable battery and/or communication module 2020is unable to communicate with an external component via wirelesscommunication component 2026 until such communication is first enabled.In such embodiments, enabling such communication is performed via nearfield communication component 2022 to ensure that devices are notaccidentally or undesirably paired with the implantable battery and/orcommunication module 2020.

In the exemplary embodiment of FIG. 20, the numbers in square boxesillustrate an exemplary sequential process for establishing wirelesscommunication between the charger 2010 and the implantable batteryand/or communication module 2020. In the illustrated embodiment, charger2010 first establishes contact with the implantable battery and/orcommunication module 2020 via near field communication components 2012,2022. In various embodiments, such near field communication is onlyoperation within very short distances, such as within two inches, forexample. This prevents other devices from accidentally or undesirablyestablishing near field communication with implantable battery and/orcommunication module 2020. During execution of this step, a user mayposition the charger 2010 proximate their pectoral region in which theimplantable battery and/or communication module 2020 is implanted toenable such communication. In some examples, after pairing the charger2010 and implantable battery and/or communication module 2020 via nearfield communication 2012, 2022, such devices can subsequentlycommunicate via wireless communication 2016, 2026.

In some embodiments, an external device 2030 (e.g., a smartphone orother audio/media source) can include a wireless communication component2036 and processor/memory 2034 capable of facilitating communicationwith implantable battery and/or communication module 2020 (e.g., viawireless communication component 2026), but may not include a near fieldcommunication component for pairing the external device 2030. Thus, insome examples, the paired charger 2010 can be configured to enablesubsequent pairing of the implantable battery and/or communicationmodule 2020 with an external device 2030.

The circled reference numerals show an order of exemplary pairing ofexternal device 2030 with an implantable battery and/or communicationmodule 2020. The charger 2010 can communicate with the external device2030 via wireless communication components 2016, 2036, for example, todetermine that a user wishes to pair the external device 2030 with theimplantable battery and/or communication module 2020. The charger 2010can then communicate with the implantable battery and/or communicationmodule 2020 (e.g., via wireless communication component 2016, 2026) topair the implantable battery and/or communication module 2020 with theexternal device 2030 to enable subsequent wireless communication betweenimplantable battery and/or communication module 2020 and the externaldevice 2030 (e.g., via wireless communication component 2026, 2036).

In some examples, once a device is paired with the implantable batteryand/or communication module 2020, it can be used to subsequently pairadditional devices to the implantable battery and/or communicationmodule as described above with respect to the charger 2010. In otherembodiments, only some devices include the ability to pair additionaldevices with the implantable battery and/or communication module 2020,such as only the charger 2010. In still further examples, every devicemust be paired with the implantable battery and/or communication modulevia a near field communication process (e.g., via field communicationcomponent 2022) before longer range wireless (e.g., Bluetooth)communication can be established.

Additionally or alternatively, once an external device is paired withthe implantable battery and/or communication module 2020, the externaldevice (e.g. external device 2030) may be used to perform additionalfunctions. In some embodiments, the additional functions may compriseadjusting a transfer function of the signal processor. In some examples,the external device includes or otherwise communicate with one or moresensors and can be configured to update the transfer function of thesignal processor based on one or more signals detected via the one ormore sensors. In some such examples, one or more such sensors caninclude a microphone, a location sensor (e.g. GPS, location based on oneor more available wireless networks, etc.), a clock, or other sensorsknown to one of ordinary skill in the art. In some embodiments, externaldevice (e.g., 2030) including or in communication with such one or moresensors includes a smartphone, tablet, or computer.

In embodiments wherein the external device includes, or is incommunication with, a microphone, the external device can be configuredto reprogram the signal processor based on information collected fromthe microphone representative of the acoustic environment. For example,the external device can be configured to identify background noise (e.g.low-end noise) and update the signal processor transfer functionaccordingly. In some such examples, the external device can beconfigured to reduce gain for low-end signals and/or emphasize othersounds or frequency ranges, such as speech or other sounds having ahigher frequency. In some embodiments, a user can initiate the processof identifying background noise for adjusting the operation of thesignal processor via the external device, for example, via a userinterface (e.g., a smartphone or tablet touchscreen).

In embodiments in which the external device includes or is incommunication with a location sensor and/or a clock, the external devicemay reprogram the signal processor based on a detected location and/ortime. For instance, in an example embodiment, when the external deviceis located in a place known to be loud (e.g. a mall or sports stadium),the external device can be configured to detect the location andautomatically reprogram the signal processor to reduce background noise(e.g., a particular frequency or range of frequencies) and/or reduce theoverall gain associated with the transfer function. Similarly, in someexamples, when located in a place in which a wearer may wish toparticularly recognize speech (e.g., a movie theater) the externaldevice can be configured to reprogram the signal processor to emphasizefrequencies associated with speech.

In some examples, the transfer function can be updated to reduce acontribution of identified background noise. In some embodiments,reducing a contribution of identified background noise comprisesemphasizing signals having frequency content between approximately 200Hz and 20 kHz. In some such examples, updating the transfer function toreduce a contribution of the identified background noise comprisesemphasizing signals having frequency content between approximately 300Hz and 8 kHz. Emphasizing signals in such frequency ranges can helpemphasize human speech or other similar signals within a noisyenvironment.

Additionally or alternatively, the external device can be configured toreprogram the signal processor based on a determined time of day. Forexample, at times when the wearer generally doesn't want to be bothered(e.g. at night), the external device can be configured to lower thevolume of all or most sounds. In some examples, the wearer mayadditionally or alternatively temporarily reprogram the signal processorvia the external device to adjust the transfer function of the signalprocessor (e.g., to reduce volume) for a predetermined amount of time(e.g. 15 minutes, 1 hour, or 1 day).

In some examples, reprogramming the signal processor comprises adjustingthe transfer function to effect a relative change (e.g., reduce volume).In some cases, reprogramming the signal processor comprises implementinga predefined transfer function in response to received data, such aslocation data indicating the wearer is in a particular location. In somesuch examples, a plurality of pre-programmed transfer functions arestored in a memory and can be implemented based on data acquired via oneor more sensors of the external device.

In some embodiments, the external device can be configured to provide aninput signal based on audio generated by the external device. Forexample, the external device can be a smartphone, and can provide aninput signal to a wearers implantable battery and/or communicationmodule comprising audio from a phone call, text to speech audio (e.g.reading a text message or an article out loud), and/or media audio (e.g.videos, music, games, etc.). The implantable battery and/orcommunication module can be configured to relay the input signal to thesignal processor for the signal processor to convert into correspondingstimulation signals.

FIG. 21 shows a process flow diagram showing an exemplary method forpairing a charger with an implanted system. The method includes turningon the charger (step 2100) and initiating a pairing process via thecharger (step 2102). The charger may instruct the user to place and holda communication coil associated with the charger over the implant (step2104). When within range of coil communication, the charger communicateswith the implant (step 2106), e.g., via an implantable battery and/orcommunication module. The charger can determine whether or not thepairing with the implant was successful (step 2108), and display to auser if the pairing was successful (step 2110) or not (step 2112).

FIG. 22 shows a process flow diagram showing an exemplary method forpairing another device with an implanted system using a paired charger.The method includes selecting an option to pair a device to an implanton the charger (step 2200), turning on the desired device and placing itin a pairing mode (step 2202). The implant determines the devicesavailable for pairing and communicates a list of available devices tothe charger (step 2204), which displays the list of available devices toa user (step 2206). The user can select from a list of displayed devicesto initiate the pairing (step 2208). The charger and/or selected devicecan determine if the pairing was successful step (step 2210). If thepairing is successful, a “pair successful” message can be displayed viathe charger and/or the newly-paired device (step 2212). If the pair wasunsuccessful, a “pair not successful” message can be displayed on thecharger (step 2214). For example, in some embodiments, after attemptingto initiate pairing between an implant (e.g., via the implantablebattery and/or communication module of a system) and another device(e.g., step 2208), if, after a predetermined amount of time, the chargerdoes not receive an indication confirming pairing from either theimplant or the selected device, the charger may determine that the pairwas unsuccessful, output the “pair not successful” message (step 2214),and stop attempting to establish the pairing.

In various examples, devices that can be paired to an implant (e.g., forcommunication with an implantable battery and/or communication module)via the charger such as via the method shown in FIG. 22 can include aremote, a smart device running an application for interfacing with theimplant, a fob, an audio streaming device, or other consumer electronicscapable of wireless communication (e.g., Bluetooth).

With reference back to FIG. 20, in various embodiments, once a device(e.g., charger 2010, external device 2030, etc.) has been paired withthe implantable battery and/or communication module 2020 for wirelesscommunication, information associated with the pairing (e.g., deviceidentifiers, etc.) can be stored in one or more memory components (e.g.,2014, 2024, 2034) so that the pairing need not be performed again in thefuture. In some embodiments, one or more devices can be unpaired fromcommunication with the implantable battery and/or communication module2020. For instance, the device can be used to disconnect from theimplantable battery and/or communication module 2020 if the device is nolonger being used by the user (e.g., discarded, returned, given away,etc.). Additionally or alternatively, a device can be automaticallyunpaired if the device has not established wireless communication withthe implantable battery and/or communication module 2020 within acertain amount of time since the last connection. For instance, in anexemplary embodiment, if a device transmitting a Bluetooth audio streamto an implanted system via the implantable battery and/or communicationmodule becomes disconnected from the implantable battery and/orcommunication module for greater than 5 minutes, the device becomesunpaired from the implantable battery and/or communication module andmust be re-paired for future use.

As described, in various embodiments, different external devices caninterface with implanted components to adjust operation of the system invarious ways. In some embodiments, not all components are capable ofperforming the same functions as other components. FIG. 23 is a chartshowing the various parameters that are adjustable by each of a varietyof external devices according to some exemplary systems. In the exampleof FIG. 23, entries in the chart including an ‘X’ represent a componentconfigured to perform a corresponding function. For instance, in theillustrated embodiment, only the charger is capable of performing aninitial wireless pairing with an implanted system, such as describedwith respect to FIGS. 20 and 21. In some such examples, the remainingdevices that can be programmed for wireless communication with theimplanted system are paired via the charger, such as described withrespect to FIG. 22. Other examples are possible in which differentcomponents include different functionality than is represented by theexample of FIG. 23, for instance, wherein components other than or inaddition to the charger can initiate wireless pairing with the implantedsystem.

Generally, the modularity of such systems allows system modifications,such as repairing, replacing, upgrading, etc., of system componentsand/or transitioning from a partially-to fully-implantable system, to beperformed with minimal disturbance of implanted system components. Forexample, an implanted cochlear electrode and electrical stimulatorand/or acoustic stimulator can remain in place while other systemcomponents are implanted and/or replaced, reducing the risk ofadditional procedures damaging the patient's cochlear tissue.Additionally, the communication techniques as described herein can beused to help customize and/or optimize a signal processor transferfunction for a particular patient, as well as enable the system to meetsafety standards, provide adequate power and data transfer rates betweensystem components, and operate at a high efficiency. It will beappreciated that, while generally described herein with respect toimplantable hearing systems, communication techniques described can beused in a variety of other implantable systems, such as variousneuromodulation devices/systems, including, for example, painmanagement, spinal cord stimulation, brain stimulation (e.g., deep brainstimulation), and the like.

In some embodiments, systems can communicate with external devices toassist in fitting and/or calibrating the implanted system. FIG. 24 showsan example configuration of an interfacing device configured to assistin system calibration. As shown, an external device 2400 (e.g., alaptop, PC, smartphone, tablet, smartwatch, etc.) communicates with afitting hub 2402. The fitting hub 2402 includes or otherwisecommunicates with a speaker 2404, which can output a sound based on acommand from the fitting hub 2402.

In the illustrated example, fitting hub 2402 includes a wirelesscommunication interface 2406 (e.g., a Bluetooth interface) that cancommunicate with a communication interface 2442 of an implantablebattery and/or communication module 2440. In some examples, the fittinghub 2402 includes or is otherwise capable of interfacing with a nearfield communication component 2408 (e.g., a communication coil) toenable Bluetooth communication between the fitting hub 2402 and animplanted system (e.g., via an implantable battery and/or communicationmodule 2440) such as described elsewhere herein. Additionally oralternatively, another device (e.g., a charger) can be used to enablewireless (e.g., Bluetooth) communication between the fitting hub 2402and the implantable battery and/or communication module 2440.

The illustrated system of FIG. 24 includes an implanted modular cochlearimplant system including an implantable battery and/or communicationmodule 2440, a signal processor 2420, a sensor 2410, a stimulator 2430,and a cochlear electrode 2416. Such components can be configured andarranged similar to various embodiments described herein and canconfigured to provide electrical signals from the stimulator 2430 viathe cochlear electrode 2416 based on signals received at the signalprocessor from the sensor 2410.

During an exemplary calibration process, the fitting hub 2402 can beconfigured to output a sound via speaker 2404 and also communicateinformation about the sound (e.g., intensity, frequency content, etc.)to the implantable battery and/or communication module 2440 of theimplanted system. The implanted system, e.g., via the signal processor2420, can be configured to compare the output of the sensor 2410(received at the signal processor 2420) to the actual sound emitted fromthe speaker 2404. This data can be repeated for a plurality of soundsfrom output from the speaker (e.g., various frequencies and/oramplitudes) and used to determine the relationships between soundspicked up from the sensor 2410 and the output from the sensor 2410 tothe signal processor 2420. Based on this information, the signalprocessor 2420 transfer function can be calibrated so that stimulationsignals sent to the stimulator 2430 based on the output from the sensor2410 accurately represent the sound from the environment. Additionallyor alternatively, the information can be used to identify howeffectively the sensor responds to various external acoustic stimuli,such as different frequencies, intensities, etc. This information can bedetermined specifically for the wearer, since the sensor response maydepend on various factors specific to the wearer and/or the positioningof the sensor.

In some embodiments, the fitting hub 2402 may be configured to outputone or more sounds comprising a single frequency and/or singleintensity. For example, each sound may have a signal frequency componentat an intensity, such as various tones. Additionally or alternatively,the one or more sounds may comprise complex frequency and intensitycomponents, such as sounds representing various beeps, words, noises, orother sounds known to one of ordinary skill in the art.

While described as taking place in the implanted system (e.g., thesignal processor 2420), the calibration process can be similarlyperformed via the fitting hub 2402. For example, the speaker 2404 canoutput a sound based on instructions from the fitting hub 2402. Thesensor 2410 can output a signal based on the sensor response to thesound emitted from speaker 2404, and the signal processor 2420 canreceive the signal from the sensor 2410 and output stimulation signalsto the stimulator 2430 based on the receives signals and the signalprocessor transfer function.

In various examples, the implantable battery and/or communication module2440 can be configured to receive any combination of the signals fromthe sensor 2410, the stimulation signals from the signal processor 2420,or signals representative of one or both of such signals. Theimplantable battery and/or communication module 2440 can thencommunicate one or more signals to the fitting hub 2402 representativeof the output of the sensor 2410 and/or the signal processor 2420 inresponse to the sound output from speaker 2404. The comparison of thesound output from the speaker 2404 and the corresponding resultingsignal(s) in the implanted system can be performed via processing in thefitting hub 2402. Similar to discussed above, this comparison can beused to determine the relationships between sounds picked up from thesensor 2410 and the output from the sensor 2410 to the signal processor2420. Based on this information, the signal processor 2420 transferfunction can be calibrated so that stimulation signals sent to thestimulator 2430 based on the output from the sensor 2410 accuratelyrepresent the sound from the environment. Additionally or alternatively,the information can be used to identify how effectively the sensorresponds to various external acoustic stimuli, such as differentfrequencies, intensities, etc. This information can be determinedspecifically for the wearer, since the sensor response may depend onvarious factors specific to the wearer and/or the positioning of thesensor.

As described, in various examples, the external device 2400 can be usedin conjunction with the fitting hub 2402. For instance, in someexamples, the external device 2400 can provide processing and controlcapabilities for processes described herein, and the fitting hub 2402can act as the interface between the external device 2400 and theimplanted system (e.g., by providing speaker 2404, wirelesscommunication interface 2406, near field communication component 2408,etc.).

In some embodiments, features and/or functions of the fitting hub 2402as described herein can be performed via the external device, such asvia a laptop, PC, smartphone, tablet, etc. including variouscapabilities described with respect to the fitting hub. For instance, anexternal device can include a speaker capable of outputting desiredsounds according to a command from the external device, as well as awireless communication interface for communicating with the implantedsystem, e.g., via implantable battery and/or communication module 2440.

In some examples, the external device 2400 and/or the fitting hub 2402may comprise a user interface in the form of an application on theexternal device. In such embodiments, features and/or functions of thefitting hub 2402 can be performed via the application. For instance, insome examples, the fitting hub can receive instructions to performfunctions via an application running on the external device 2400. Insome such embodiments, a wearer and/or physician can provide an inputvia the application, for example, during various processes describedherein. In some embodiments, a wearer can receive a sound from thefitting hub 2402 and provide input, via the application, indicatingwhether the sound was heard or not heard, was too loud or too quiet, wasdistinguishable or not distinguishable from a previous sound, and/orother inputs. In some examples, an implant system (e.g., via fitting hub2402 or implantable battery and/or communication module 2440) can beconfigured to update a signal processor transfer function in response tosuch received inputs.

In some embodiments, the fitting hub 2402 and/or the external device2400 may be configured to communicate to a remote facility, for example,with a physician such as an audiologist. In some such embodiments, thefitting hub 2402 and/or the external device 2400 includes a remotecommunication device 2407 configured to communicate with such a remotefacility, for example, via the internet. The remote communication device2407 can communicate various information associated with the fitting hub2402, the external device 2400, and the implanted cochlear implants, toan additional device, such as a device used by an audiologist.Additionally or alternatively, the remote communication device 2407 canbe configured to receive inputs from such an additional device, such asinputs related to features and/or functions performed by the fittinghub, the external device, and/or the implanted cochlear implants. Forexample, in some instances, an audiologist operating at a remotefacility can trigger the fitting hub 2402 to output one or morepredetermined sounds and/or perform one or more fitting functions.Additionally or alternatively, the audiologist can receive informationsuch as how often the wearer uses and/or updates features of thecochlear implant system.

In an example implementation, a physician can receive diagnosticinformation regarding any testing or other processes performed by theexternal device 2400, the fitting hub 2402, and/or the implantedcochlear implant system via the remote communication device 2407. Insome such examples, the physician may receive data regarding how oftentests or other processes are performed, the results of any performedtests or processes, how often various devices (e.g. fitting hub 2402)are used, and/or any feedback regarding the use or usability of theimplanted cochlear implants.

In some examples, the physician can initiate or perform various tests orother processes from an additional device via the remote communicationdevice 2407. In some embodiments, features and/or functions of thefitting hub 2402 as described herein can be performed or initiated by aphysician using an additional device via the remote communication device2407. In various examples, the physician can perform various features,such as providing one or more sounds via a speaker (e.g., 2404),performing a stapedial reflex test, or the like as described herein. Thephysician can receive one or more signals representative of the outputof the sensor 2410 and/or the signal processor 2420 in response to theprovided one or more sounds from the speaker. A comparison of theprovided one or more sounds form the speaker and the correspondingresulting signal(s) in the implanted system can be performed by theadditional device and/or by the physician receiving such information viathe additional device.

In some embodiments, the remote communication device 2407 maycommunicate with an additional device (e.g., at a physician's remotefacility) via a wireless connection (e.g. Bluetooth, Wi-Fi, NFC,cellular network, internet access, etc.). While the remote communicationdevice 2407 is depicted as communicating via the external device 2400,the remote communication device 2407 can additionally or alternativelycommunicate via the fitting hub 2402, or a different component of thesystem. In various embodiments, such a remote communication device canbe integrated into the external device 2400 and/or the fitting hub 2402.In some embodiments, the remote communication device 2407 and thewireless communication interface 2406 may be integrated together tofacilitate communication with a remote facility and an implanted system.Alternatively, the remote communication device 2407 and the wirelesscommunication interface 2406 may be separate, or partially separatecomponents.

FIG. 25 is a process flow diagram showing an example process forcalibrating an implanted system. In some examples, one or more sensors(e.g., a sensor contacting the incus such as sensor 540 shown in FIG. 5)can detect a physiological phenomenon known as a stapedial reflex, inwhich muscles in the middle ear contract in response to various stimuli,such as loud sounds or the expectation of loud sounds. In some examples,an implanted signal processor in communication with such a sensor canrecognize the occurrence of a stapedial reflex based on a characteristicoutput, for instance, via preprogrammed signal recognition or via alearning process, in which the stapedial reflex is triggered and theresponse from the sensor is measured and learned.

The calibration process of FIG. 25 includes applying electricalstimulation at a predetermined intensity (step 2500) and measuring aphysiological response via a middle ear sensor (step 2510). The measuredphysiological response can be used to detect whether or not a stapedialreflex has occurred (step 2520). If a stapedial reflex is not detected,the intensity of the electrical stimulation is increased (step 2530),and electrical stimulation at the new intensity is applied (step 2500)and the physiological response is measured (step 2510). This process canbe repeated until the stapedial reflex is detected at step 2520.

Once the stapedial reflex is detected, the intensity that caused thestapedial reflex can be mapped to a predetermined sound pressure level(step 2540). For instance, in some examples, the lowest electricalintensity determined to cause the detected stapedial reflex can bemapped to an input sound pressure of 100 dB. The method can includecalibrating stimulation intensities as a function of sound pressurelevel (step 2550) based on the mapping of the stapedial reflex-causingintensity to the predetermined sound pressure level.

The calibration process of FIG. 25 can be initiated in a variety ofways. For example, in various embodiments, the process can be initiatedby one or more components in communication with the implanted system,such as a programmer, charger, external device, fitting hub, or thelike. Such processes can be performed during an initial fitting and/or acalibration after a period of use of the system.

Leveraging fully implanted system and initiating the process via awireless communication (e.g., from a programmer, fitting hub, externaldevice etc.), greatly simplifies the process of triggering and/ordetecting the stapedial reflex. For example, utilizing a cochlearelectrode (e.g., 2416) to cause the stapedial reflex and sensing thereflex using an implanted middle ear sensor eliminates the need fortedious diagnostic equipment such as tympanometry equipment foranalyzing a stapedial reflex.

In some examples, the systems and processes described with respect toFIG. 24 can be used in the calibration steps discussed with respect toFIG. 25. For instance, in an illustrative example, the fitting hub 2402of FIG. 24 can cause a speaker 2404 to produce a sound having a soundpressure level of 100 dB while also communicating (e.g., via Bluetoothcommunication) the details of the sound (e.g., intensity, frequency,etc.) to the implantable battery and/or communication module 2440. Theoutput of the sensor 2410 in response to the 100 dB sound can beidentified and associated with the lowest electrical stimulationintensity that causes the detected stapedial reflex. Such a process canbe repeated for a plurality of frequencies to link various externalacoustic stimuli (e.g., from speaker 2404) to particular electricalstimulations.

Several embodiments discussed herein generally relate to a cochlearimplant system. As discussed herein, cochlear implant systems cancomprise a cochlear electrode implanted into the cochlear tissues of awearer, as well as various other components such as an electricalstimulator, signal processor, and a middle ear sensor. In someembodiments, the cochlear implant system comprises components implantedinto one or both sides of a wearer. For example, a system can comprisecomponents implanted in a wearer's left side (e.g. for their left ear),their right side (e.g. for their right ear), or both.

FIG. 26 shows an example embodiment wherein the cochlear implant systemcomprises components implanted for both sides of the wearer (e.g. forboth their right ear and their left ear). As shown, the cochlear implantsystem of FIG. 26 comprises a first subsystem comprising a firstcochlear electrode 2616 a, a first electrical stimulator 2630 a, a firstmiddle ear sensor 2610 a, and a first signal processor 2620 a, and asecond subsystem comprising a second cochlear electrode 2616 b, a secondelectrical stimulator 2630 b, a second middle ear sensor 2610 b, and asecond signal processor 2620 b. The first subsystem and the secondsubsystem can be configured similarly to other cochlear implant systemsdiscussed herein. In some embodiments, the first electrical stimulator2630 a and the first signal processor 2620 a can be housed in a firsthousing with the first cochlear electrode 2616 a extending from thefirst housing. Additionally or alternatively, the second electricalstimulator 2630 b and the second signal processor 2620 b can be housedin a second housing with the second cochlear electrode 2616 b extendingfrom the second housing.

The cochlear implant system of FIG. 26 comprises an implantable batteryand/or communication module 2640. In some embodiments, the cochlearimplant system can comprise a plurality of implantable battery and/orcommunication modules, even though not shown in FIG. 26. The implantablebattery and/or communication module 2640 can be configured to adjust afirst transfer function associated with the first signal processor 2620a and adjust a second transfer function associated with the secondsignal processor 2620 b.

In some such embodiments, the implantable battery and/or communicationmodule 2640 can be in communication with the first signal processor 2620a via a first lead 2670 a and be in communication with the second signalprocessor 2620 b via a second lead 2670 b. In some such embodiments,such as shown in FIG. 26, the first lead 2670 a may be different thansecond lead 2670 b.

Additionally or alternatively, the implantable battery and/orcommunication module 2640 can be in communication with both the firstsignal processor 2620 a and the second signal processor 2620 b via abifurcated lead 2675. In some such examples, the implantable batteryand/or communication module 2640 can be configured to simultaneouslysend an output signal to each of the first signal processor 2620 a andthe second signal processor 2620 b via the bifurcated lead 2675. In someembodiments, the implantable battery and/or communication module 2640provides the same output signal to both the first signal processor 2620a and the second signal processor 2620 b. The implantable battery and/orcommunication module 2640 can be configured to communicate addressedoutput signals to the first signal processor 2620 a and the secondsignal processor 2620 b via the bifurcated lead 2675, wherein theaddressed output signals comprises address information designating atleast one of the first signal processor 2620 a and the second signalprocessor 2620 b. In some such embodiments, first signal processor 2620a and second signal processor 2620 b can be configured to detect theaddress information and respond only to signal addressing the particularsignal processor. For instance, in some examples, the first signalprocessor 2620 a may be unaffected by an addressed output signalcomprising address information designating the second signal processor2620 b and not the first signal processor 2620 a. Similarly, the secondsignal processor 2620 b may be unaffected by an addressed output signalcomprising address information designating the first signal processor2620 a and not the second signal processor 2620 b. Alternatively, thebattery and/or communication module 2640 may communicate either the samesignal or a different signal to first signal processor 2620 a and secondsignal processor 2620 b without bifurcated lead 2675, such as anembodiment having two separate outputs from the battery and/orcommunication module 2640.

As discussed herein, an implantable battery and/or communication modulecan be configured to communicate with a signal processor to adjust atransfer function associated therewith. In some examples, theimplantable battery and/or communication module 2640 can be configuredto adjust the first transfer function for the first signal processor2620 a, the second transfer function for the second signal processor2620 b, or a combination of the two, for example, in response to areceived command. In such embodiments, the implantable battery and/orcommunication module 2640 may be configured to receive the commands fromthe external device via a wireless communication interface (e.g.Bluetooth, Wi-Fi, NFC, etc.).

In some embodiments, the cochlear implant system can receive a commandto change a volume associated with the cochlear implant system. In someembodiments, the volume associated with the cochlear implant system maybe an overall volume or a volume of a specific range of frequenciesand/or tones (e.g. reduction of background noise, emphasis of speech, anincrease of volume from one source relative to another, etc.). In someexamples, the implantable battery and/or communication module 2640 canbe configured to, in response to a command to change the volume, adjusta relative volume of both the first transfer function and the secondtransfer function by approximately the same amount.

However, in some examples, a wearer may have different amounts or typesof hearing loss on one side vs the other. In such examples, increasingthe volume of the first transfer function the same as the secondtransfer function may not correlate to a patient perceiving the samerelative volume change on both sides. As such, the first transferfunction and the second transfer function may be updated such that thepatient perceives a similar change in output via the first electricalstimulator 2630 a and the second electrical stimulator 2630 b inresponse to a given stimulus.

In response to the command to change the volume, the implantable batteryand/or communication module 2640 can be configured to determine anexisting first transfer function associated with the first signalprocessor 2620 a and determine an updated first transfer function basedon the determined existing first transfer function and the receivedcommand. Additionally, the implantable battery and/or communicationmodule 2640 can be configured to determine an existing second transferfunction associated with the second signal processor 2620 b anddetermine an updated second transfer function based on the determinedexisting second transfer function and the received command. In suchembodiments, the updated first transfer function and the updated secondtransfer function may reflect a change in perceived volume as prescribedin the received command. However, the changes to the first transferfunction and the second transfer function need not be the same, despiteresulting from the same received command.

For instance, in some embodiments, in response to a command to change avolume, the implantable battery and/or communication module can beconfigured to individually change a volume associated with the firsttransfer function and a volume associated with the second transferfunction. In some such embodiments, the adjustment to the first transferfunction may reflect the same or a different adjustment than theadjustment to the second transfer function. In an example embodiment, inresponse to receiving a command to change the volume, the implantablebattery and/or communication module can be configured to adjust thevolume of the first transfer function by more or less than the secondtransfer function, such that a wearer perceives more or less change inthe stimulation output via the first electrical stimulator 2630 a thanthe second electrical stimulator 2630 b.

Transfer functions associated with separate signal processors can beupdated differently in response to a common command (e.g., “increasevolume”) in order to accommodate for different hearing profilesassociated with each subsystem. For instance, in an example embodiment,a first subsystem and a second subsystem can be programmed withdifferent transfer functions based on, for example, the wearer's hearingprofile in the left and right ears, the operation of a middle ear sensorin each of the first and second subsystems (which might behavedifferently based on, for example, a wearer's anatomy), and the like. Acommand to “increase volume” might result in different adjustments tothe different transfer functions. For example, a first transfer functionmight increase a gain by 10% while the second transfer function mightincrease a gain by 20% in one or more frequency ranges. Each change canbe determined, for example, based on a prescribed response to a givencommand based on an existing transfer function.

In some embodiments, systems including two different subsystems, such asshown in FIG. 26, can be used to perform various functions describedherein, such as detecting a stapedial reflex in a wearer. In an exampleembodiment, an acoustic stimulus can be provided to a first ear of thewearer, such as via an in-ear speaker (e.g., in communication with afitting hub). The acoustic stimulus can be detected via first middle earsensor 2610, which can provide an input signal to the first signalprocessor 2620 a programmed with a first transfer function and output acorresponding stimulation signal to the first electrical stimulator 2630a. The first electrical stimulator 2630 a can provide an electricalstimulus to the wearer's cochlear tissue based on the stimulationsignal.

The implantable battery and/or communication module 2640 can receiveinformation from the second signal processor 2620 b representing datareceived from the second middle ear sensor 2610 b. Generally, astapedial reflex occurs in the inner ear of both sides of a person, evenif the stimulus is applied to only a single ear. Accordingly, theimplantable battery and/or communication module 2640 can be configuredto detect a stapedial reflex triggered in the wearer based on theinformation received from the second signal processor 2620 b in responseto the stimulus detected by the first middle ear sensor 2610 a.

In some embodiments, this phenomenon can be leveraged in order toperform various stapedial reflex processes described herein. Forexample, a fitting hub can provide a stimulus of increasing intensity toa first ear of a wearer until the implantable battery and/orcommunication module detects a stapedial reflex in the other ear of thewearer. Similar to described elsewhere herein, the intensity the soundthat triggered the stapedial reflex can be used to calibrate thetransfer function of the signal processor associated with the sensorused in the first ear. Such a process can be repeated for a plurality offrequencies and for the other ear.

Various non-limiting embodiments have been described. These and othersare within the scope of the following enumerated embodiments.

1. A cochlear implant system comprising: a cochlear electrode; astimulator in electrical communication with the cochlear electrode; amiddle ear sensor configured to receive a stimulus signal and generatean input signal based on the received stimulus signal; and a signalprocessor in communication with the stimulator and the middle earsensor, the signal processor having an analog processing stage and adigital processing stage and being programmed with a transfer functionand being configured to: receive the input signal from the middle earsensor; input the received input signal to the analog processing stageand process the received input signal via the analog processing stage togenerate an analog processed signal; input the analog processed signalto the digital processing stage and process the received analogprocessed signal via the digital processing stage to generate adigitally processed signal, the digitally processed signal correspondingto a normalized stimulus signal having reduced gain variability across arange of frequencies and compensating for variability in the frequencyresponse of the middle ear sensor; and output a stimulation signal tothe stimulator based on the digitally processed signal and the transferfunction.
 2. The cochlear implant system of claim 1, wherein processingthe received input signal via the analog processing stage comprisesflattening a frequency response curve of the received input signal. 3.The cochlear implant system of claim 2, wherein the analog processingstage includes one or more filters and/or amplifiers.
 4. The cochlearimplant system of claim 1, wherein the stimulator and the signalprocessor are integrated into a single hermetically sealed housing, andwherein the cochlear electrode extends from the single hermeticallysealed housing.
 5. The cochlear implant system of claim 4, wherein thesingle hermetically sealed housing includes an outer surface having afirst side, a second side generally opposite the first, and a returnelectrode coupled to the outer surface on both the first side and thesecond side.
 6. The cochlear implant system of claim 1, wherein thesignal processor is configured to apply the transfer function to thegenerated digitally processed signal to generate the stimulation signal.7. The cochlear implant system of claim 1, wherein the digitalprocessing stage is adjustable to calibrate the signal processor to themiddle ear sensor.
 8. The cochlear implant system of claim 7, furthercomprising an external device in communication with the signalprocessor, and wherein the external device is configured to receive thedigitally processed signal generated by the signal processor and adjustthe digital processing stage to change the frequency response of thedigital processing stage.
 9. The cochlear implant system of claim 8,further comprising an implantable battery and/or communication module incommunication with the signal processor and configured to communicatewirelessly with the external device to facilitate communication betweenthe external device and the signal processor.
 10. The cochlear implantsystem of claim 1, wherein the signal processor is configured to:receive a broad-spectrum input signal corresponding to a broad-spectrumstimulus signal received at the middle ear sensor comprising a pluralityof frequencies; and determine the frequency response of the analogprocessing stage and the digital processing stage.
 11. The cochlearimplant system of claim 10, wherein the signal processor is configuredto adjust the digital processing stage to normalize the frequencyresponse of the combined analog processing stage and digital processingstage based on a Fast Fourier Transform of the broad-spectrum stimulussignal and/or broad-spectrum input signal.
 12. The cochlear implantsystem of claim 1, wherein the signal processor is configured to receivea plurality of input signals, each being representative of a stimulussignal having unique frequency content, and determine the frequencyresponse of the analog processing stage and the digital processingstage.
 13. The cochlear implant system of claim 12, wherein the signalprocessor is further configured to adjust the digital processing stageto normalize the frequency response of the combined analog processingstage and digital processing stage.
 14. The cochlear implant system ofclaim 13, wherein normalizing the frequency response of the combinedanalog processing stage and the digital processing stage makes a ratioof a digital processed signal to a received corresponding stimulussignal approximately consistent across a plurality of frequencies orfrequency ranges.
 15. A method of compensating for variability in amiddle ear sensor comprising: receiving a stimulus signal via a middleear sensor, generating, with the middle ear sensor, an input signalbased on the stimulus signal; applying an analog filter to the generatedinput signal to generate an analog filtered signal; applying a digitalfilter to the generated analog filtered signal to generate a digitallyfiltered signal; measuring a frequency response of the digitallyfiltered signal and/or the analog filtered signal with respect to theinput signal; and adjusting the digital filter to normalize thefrequency response of the digitally filtered signal with respect to thestimulus signal.
 16. The method of claim 15, wherein: the stimulussignal comprises a broad-spectrum stimulus signal; and measuring afrequency response of the digitally filtered signal and/or the analogfiltered signal with respect to the input signal comprises performing atransform of the broad-spectrum signal to determine the frequencycontent thereof and determining the frequency response based on thedetermined frequency content.
 17. The method of claim 15, furthercomprising applying a plurality of stimulus signals to the middle earsensor having known frequency content, and wherein the measuring thefrequency response of the digitally filtered signal with respect to thestimulus signal is performed for each of the plurality of stimulussignals.
 18. The method of claim 17, wherein the applying the pluralityof stimulus signals comprises applying stimulus signals havingfrequencies ranging between 100 Hz and 10 kHz.
 19. The method of claim17, wherein measuring the frequency response of the digitally filteredsignal with respect to the received stimulus signal comprises, for aplurality of frequencies or frequency ranges, determining a ratio of amagnitude of the digitally filtered signal to a magnitude of thestimulus signal.
 20. The method of claim 19, wherein adjusting thedigital filter to normalize the frequency response with respect to thereceived stimulus signal comprises adjusting the digital filter so thatthe determined ratio is approximately equal for each of the plurality offrequencies or frequency ranges.
 21. The method of claim 15, whereinapplying an analog filter to the generated input signal comprisesapplying a plurality of analog filters and/or analog amplifiers.
 22. Themethod of claim 21, further comprising adjusting the analog filter tonormalize the frequency response of the digitally filtered signal withrespect to the stimulus signal.
 23. A system comprising: a cochlearelectrode; a stimulator in electrical communication with the cochlearelectrode; a middle ear sensor configured to receive a stimulus signaland generate an input signal based on the received stimulus signal; anda signal processor in communication with the stimulator and the middleear sensor, the signal processor having an analog processing stage and adigital processing stage and being programmed with a transfer functionand being configured to: receive the input signal from the middle earsensor; input the received input signal to the analog processing stageto generate an analog processed signal; input the analog processedsignal to the digital processing stage to generate a digitally processedsignal, the digitally processed signal corresponding a normalizedstimulus signal to reduce variability in a frequency response of themiddle ear sensor; and output a stimulation signal to the stimulatorbased on the digitally processed signal and the transfer function.